Vehicle Restraints vs Wheel Chocks: What Each One Holds, and What OSHA Actually Requires

Vehicle restraints and wheel chocks differ in fit, holding method and feedback—not just ratings. A monitored restraint can add engagement signals that a loose chock lacks, but some chocks are monitored restraints. The Occupational Safety and Health Administration (OSHA) keeps chock language in its regulation; its mechanical-restraint alternative is conditional. The device must fit the trailer and the operating procedure.

Last verified: September 2026. Trailer Securement Ledger, data edition 1.2.0, compiled September 2026. The source documents keep their own dates and editions.

The quick comparison

Here is the whole argument in one table. Everything after it is the evidence.

Sources: MHI/MH30.3 public scope; SAE J348 publisher listing; 29 CFR 1910.178; 1910.26; STD 01-11-007; named-model sources in the restraint spec table and chock table. U.S. application, verified September 2026. Wheel-dependent and monitored-chock configurations are explained below rather than forced into these two columns.

Uptime Dock & Door Research is the independent research and reference section of uptimedockanddoor.com. Uptime is a commercial service-referral publisher, not a repair contractor, manufacturer, laboratory, standards body or agency. See our editorial policy for how we verify and correct this material.

Our read: for a compatible trailer and dock, a monitored RIG restraint adds a connection to the guard and status communication that a loose, unmonitored chock lacks. That is an editorial judgment based on the verified rows above, not a claim from a test that compared them head to head. No such test appears in any source we read.

But the comparison stops being useful the moment the trailer is one the restraint cannot hold. That is where most of this page lives.

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Key numbers

★ Source-reported means we checked it in the cited primary source. ● Calculated means we computed it from cited inputs and show the formula. Both are verified. Manufacturer-reported does not mean independently tested.

1. ● 12 of 15 selected restraint models contain a manufacturer-stated force figure. The printed numbers are 30,000, 32,000, 35,000 and 40,000 lb, with qualifiers such as “up to” and “in excess of” retained. These are not an equivalent-capacity range or a comparative safety result. Five manufacturer brands; the source-linked specification table, verified September 2026.
2. ● 13 of 15 selected restraint models publish both vertical engagement endpoints. Their lower endpoints run 7–12 inches and upper endpoints 25–34 inches. A published window is not a complete trailer-fit test. Our calculation from the restraint spec ledger.
3. ● Six named Checkers chock products are documented here; their cited rating fields do not provide a measured pull-out force. Five list gross vehicle operating weights from 20,000 to 1,600,000 lb. The largest figure carries a minimum-four-chock condition at 855,000–1,600,000 lb. The chock table, not a market-wide finding.
4. ★ 560 mm (22 inches) is the maximum ground clearance in 49 CFR 393.86(a)(3) for the trailers covered by paragraph (a)(1), subject to its rounded-end exception. Those clauses specify no minimum ground clearance; that is not a legal zero-height limit. FMCSA rear-guard rule.
5. ★ Three conditions attach to OSHA's mechanical-restraint alternative: effective movement prevention, manufacturer-compliant installation/maintenance/use, and immediate removal of damaged equipment. STD 01-11-007, F.1–F.3, 5 August 1981.
6. ★ Two OSHA documents on this subject were withdrawn: a 4 March 1998 letter and a 1 April 1991 memorandum. OSHA interpretation, 7 March 2011.
7. ★ 22 State Plans cover private-sector workers. Federal jurisdictional limits do not automatically settle State Plan authority. Current OSHA directory and 14 June 2011 interpretation; checked September 2026.
8. ★ 9 December 2021 is the effective date for adding rear impact guards to the federal annual vehicle inspection criteria. 86 FR 62105; Appendix A to 49 CFR Part 396, item 15.
9. ★ 23 March 2026 is the effective date of the Federal Motor Carrier Safety Regulations (FMCSRs) rear-impact-guard label-requirement rescission. It did not remove the FMVSS duty on guard manufacturers. 91 FR 7874.

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On this page

• The quick comparison
• Why "which one holds more" has no straight answer
• What each device actually is
• Does OSHA still require chocks if you have a restraint?
• What the restraint is grabbing: the rear impact guard
• What 15 restraint models publish
• Where a restraint can't engage: 18 conditions
• What the manufacturers say about keeping chocks
• What a chock rating actually means
• How to choose
• Keeping either one working
• What we could not confirm
• How we built this
• Sources
• How to cite this page
• Download the data
• Questions people ask

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Why "which one holds more" has no straight answer

Because the ratings in this comparison measure different things: a restraint force and a chock’s vehicle-weight/application rating.

That sounds like a dodge. It isn't. It is a difference you can check in the two product pages linked below.

Pull up a restraint spec sheet and you will find a number like this: restraining force in excess of 35,000 lb. It is a force. Pounds-force. It is the maker’s stated restraining capacity, not a documented failure or release threshold.

Now pull up a chock spec sheet. You will find a number like this: rated for vehicles with gross vehicle operating weight up to 20,000 lbs and on slopes up to 11% grade. That is not a measured pull-out force. It is a vehicle-weight rating plus a slope condition; other chock pages also specify tire diameter. It describes the biggest vehicle the maker says the chock suits.

Both numbers use pounds, but they describe different quantities and test conditions.

Sources: Poweramp PowerHook product page and Checkers UCTS003 product page, verified September 2026. GVW means gross vehicle weight. These two source-reported figures are not a head-to-head test.

The comparison cannot be made by putting those two numbers side by side. A vehicle-weight rating does not supply the missing pull-out measurement.

Why a chock rating is built that way

The vehicle, tire and approach are part of a chock’s application. Checkers’ selector asks for vehicle weight, tire diameter and traction conditions. Its reference guide gives an 8% grade as its chart’s test basis and calls for application testing.

That is why a gross vehicle weight alone is not a complete selection. Change the surface or tire and you need to check the application again. The guide’s test grade is not a universal slope limit for every chock.

Sources: Checkers wheel-chock selector and Checkers Wheel Chock Reference Guide, CK407r1-guide(0325), copyright 2025, verified September 2026.

None of this means chocks do nothing. It means the two published ratings do not answer the same question, and the useful question is narrower: can the restraint engage this trailer, and if not, what is holding it?

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What each device actually is

The two restraint families

ANSI MH30.3, Vehicle Restraining Devices: Performance and Testing, is the American National Standard for this equipment. It is published by the Loading Dock Equipment Manufacturers group of MHI. It is a voluntary consensus standard, not automatically a legal requirement; adoption, a contract or an equipment requirement can make a standard relevant to a particular job. Its public scope describes a vehicle restraining device as a manufactured structure between the dock and the vehicle, intended to limit vehicle creep—gradual trailer movement away from the dock—and prevent unscheduled departure, or a trailer pulling away before loading is complete.

It covers two types:

• Rear impact guard (RIG) type. Engages the horizontal bar across the back of the trailer. The standard notes these are also called ICC bar restraints. MHI describes RIG-dependent restraints as the most common type.
• Wheel dependent type. Engages one or more wheels instead.

Either type can be manually operated or power operated. That is a separate question from which type it is — a mechanical hook you crank with a rod is still a RIG restraint.

The standard was first approved in December 1993 and revised in 2000, 2005 and 2015. MHI lists a 2022 edition as current. We read the 2015 edition's published preview, which is the scope, definitions, contents and clause headings that ANSI makes freely available. We did not buy the standard, so we do not quote clause text from it, and nothing on this page depends on a clause we have not read. Sources: 2015 public preview, MHI listing and 2022 publisher listing, checked September 2026.

A word on "ICC." ICC stands for Interstate Commerce Commission, the agency that first required rear-end protection on heavy vehicles in 1952. An intermodal container chassis is a different term. Source for the 1952 rule and issuing agency: FMCSA’s 2021 rule history.

A wheel chock is a wedge. Except when it isn't.

A wheel chock is a shaped block placed against a tire so the tire has to climb it to move. The loose products in our table use polyurethane, high-density polyethylene or rubber. Someone has to carry them out.

Here is the part that breaks the tidy two-column comparison: some wheel chocks are sold as vehicle restraints.

Rite-Hite's GWC-1000 Global Wheel Chock sits inside that company's vehicle restraint product line, under wheel-based restraints. The product page describes a manually positioned chock with an ultra-sonic sensor on a ten-foot coil cord that detects the tire and drives the same interior and exterior light communication as the company's hook restraints. Rite-Hite states it is certified to meet and exceed ANSI MH30.3 performance testing standards, and describes it as securing liftgate, delivery and parcel trucks and trailers without rear impact guards — vehicles, in the manufacturer's own words, that traditional restraints cannot engage. The page does not name an independent certifying body, so we report that as a manufacturer claim. Source: Rite-Hite GWC-1000 product page, verified September 2026.

So the real question at a dock is not "restraint or chock." It is three separate questions, and they have different answers:

1. What holds the vehicle? A connection to the guard, a wheel-based mechanism, or a chock against a tire.
2. How is it applied? By a powered mechanism, or by a person walking out.
3. What confirms and communicates it? A sensor and lights, or nothing.

A loose rubber chock needs manual placement and has no built-in feedback. A monitored engineered chock can still need manual placement while adding sensing and lights. They are both "wheel chocks." Anybody comparing categories instead of configurations will get this wrong.

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Does OSHA still require chocks if you have a restraint?

The chock language is still in the regulation. OSHA’s mechanical-restraint alternative carries three conditions: effective movement prevention, manufacturer-compliant installation/maintenance/use, and immediate removal of damaged equipment. It is not a blanket exception attached to buying a dock lock. Sources: 1910.178 and STD 01-11-007, F.1–F.3.

Here is the whole chain.

What the rules actually say

Read these provisions next to each other, because they cover different operations and use different wording.

Sources: 29 CFR 1910.178(k)(1), (k)(2), (m)(7) and 29 CFR 1910.26(d), verified September 2026. This table compares the regulation text; the directive and jurisdiction discussion below must be read with it.

Two things worth noticing.

First, railroad cars have flexible wording and highway trucks do not. Rail has “other recognized positive protection”; the highway-truck paragraph expressly names chocks. The mechanical-restraint directive addresses an alternative to the truck requirement.

Second, 1910.26(d) reaches beyond powered industrial trucks. It applies within general industry while employees are on a dockboard. OSHA's definition of “dockboard” includes dock levelers, so an employee crossing a leveler with a manual pallet jack is not outside paragraph (d) merely because no forklift is involved. Sources: 1910.26(d) and 1910.21(b).

The 1981 directive, and its three conditions

OSHA Instruction STD 01-11-007 (originally STD 1-11.7), issued 5 August 1981, sets out the conditional mechanical-restraint alternative. Its conditions matter as much as its conclusion.

It says failure to use wheel chocks will be treated as a de minimis violation and will not be cited, under the following conditions:

1. A positive mechanical means secures trucks or trailers to the dock, installed and used in a manner that effectively prevents movement during loading, unloading and boarding by hand trucks and powered industrial trucks.
2. All of the mechanical equipment is installed, maintained and used as recommended by the manufacturer.
3. Any damaged mechanical equipment is removed from service immediately.

Read conditions two and three again. The allowance does not attach to the purchase alone. It attaches to effective movement prevention and how the equipment is installed, maintained and used.

If required maintenance is overdue or the equipment is damaged, do not assume the installation still meets those conditions. The manufacturer’s requirements and the actual equipment condition are what you need to check. Source: STD 01-11-007, F.1–F.3.

"De minimis" does not mean approved

A de minimis violation is one OSHA does not cite because it has no direct or immediate relationship to safety and health. Source: U.S. Department of Labor, Employment Law Guide.

It is not a product approval. OSHA does not approve or endorse products. A supplier’s “OSHA-approved” dock-lock claim is not established by this directive. Source: OSHA product-approval guidance.

The 2005 letter that names dock locks out loud

On 14 September 2005, OSHA replied to a letter about chocking at Postal Service facilities. It restated the policy in plain terms: in light of changes in technology, failure to use chocks will be treated as de minimis and not cited where alternative methods prevent truck movement. The letter names dock lock mechanisms, dock monitoring systems, or other systems that prevent unintended movement of trucks and trailers.

The letter is still published by OSHA. The named alternatives must prevent unintended movement; a status light alone is not a movement-prevention device. Source: 14 September 2005 interpretation.

The commercial-vehicle argument, and exactly where it stops

This is the part that gets repeated as a blanket exemption. It is not one.

OSHA's position, set out in its 8 November 2005 and 7 March 2011 letters of interpretation, is that FMCSA's braking rules preempt OSHA's chocking requirements as applied to operators of commercial motor vehicles. FMCSA told OSHA in 2001 that 49 CFR 393.41(a), which requires both the availability and the use of a parking brake system, covers the same ground.

A commercial motor vehicle (CMV) is a defined legal category, not simply any delivery vehicle. Use the definition and the employer/working-condition distinctions identified in the cited OSHA interpretations.

Then the 2011 letter draws the line that matters to a warehouse:

Because the FMCSA parking brake regulations do not apply to vehicles which are not CMVs, OSHA is not pre-empted from enforcing its chocking requirements with respect to those vehicles. Furthermore, because the FMCSA parking brake regulations do not apply to companies which do not own, operate, or lease CMVs, OSHA is not pre-empted from enforcing standards requiring such companies to take precautions to protect their workers, such as forklift operators, from the movement of trailers.

If you run a warehouse and you do not own, operate or lease CMVs, the carrier’s federal preemption argument does not erase your duty to protect your own workers from trailer movement. Source: OSHA’s 7 March 2011 interpretation.

The same letter adds a second point people miss. Under the powered industrial truck training provisions, an operator must be trained not to drive onto a trailer at the dock unless it is secured or restricted from movement first. That duty does not depend on whose truck it is.

The applicable parking-brake performance clauses include testing conditions for a public road free of ice and snow. That wording is a brake-performance condition, not a rule that changes OSHA/FMCSA jurisdiction whenever the weather changes. Source: 49 CFR 393.41.

State Plans can apply different rules

A federal jurisdictional answer does not automatically settle a State Plan case.

On 14 June 2011, OSHA answered the American Trucking Associations after a Washington State inspector cited a motor carrier at the carrier's own terminal yard for not chocking during loading and unloading. OSHA's reply is direct:

the OSHA jurisdictional limits pursuant to Section 4(b)(1) of the Federal Act and relevant case law are not directly applicable to the State Plans. The 22 State Plans covering the private sector are not required to have a provision equivalent to Section 4(b)(1) in their State enabling legislation and may have different statutory language regarding overlap of jurisdictional authority with other Federal agencies.

The 2011 letter said Washington did not have an equivalent provision in the case discussed, that an employer could challenge a state citation on jurisdictional grounds, and that the matter must ultimately be resolved under state law. This is the letter’s historical Washington discussion, not a new determination of current Washington law. OSHA’s current directory separately confirms 22 State Plans covering private-sector workers. Sources: 2011 interpretation and State Plans directory.

So the commercial-vehicle exemption is a federal position. In a state-plan state it may not apply at all.

And some states wrote the answer straight into the rule. California's 8 CCR 3650(t)(22) reads:

Vehicles shall not be driven in and out of highway trucks and trailers at loading docks until such trucks or trailers are securely blocked or restrained and the brakes set.

The alternative is in the California regulation text. Source: 8 CCR 3650(t)(22).

We read one state's rule, not fifty. To check yours: find your state on OSHA's State Plans directory, open that agency's general industry standards, and look for its powered industrial truck section rather than assuming it copies 1910.178 word for word.

The chocking policy timeline

Nineteen documentary records, 1952 to 2026. We assembled this from OSHA’s own directives and letters and from the Federal Register. Some earlier events are described in later issuer histories rather than a newly retrieved copy of the original document.

Sources: the issuer links in each row and the downloadable policy timeline, which records exact locators, document periods and verification dates. Verified September 2026. Historical guidance is not automatically current operating guidance.

Two date conflicts remain in the issuer’s own history. OSHA’s 2011 narrative dates STD 1-11.5 to 30 October 1978; the 1981 directive’s reference names 31 January 1978. For CPL 02-01-030, OSHA’s directive index gives 19 October 1999 while the 2011 narrative says 1 October. We retain those differences rather than silently choosing a date. Sources: 2011 history, 1981 directive and OSHA directive index.

If you are quoting the 1998 Blumenthal letter or the 1991 memorandum, you are quoting withdrawn guidance. OSHA says so in the 2011 letter.

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What the restraint is grabbing: the rear impact guard

A hook restraint does not grab the trailer. It grabs the horizontal guard bar across the back of it — a bar the federal government requires for a completely different reason.

The rear impact guard, or RIG, exists to stop a car sliding underneath a trailer in a rear-end crash. A RIG-dependent restraint relies on a component designed for underride protection.

So it is worth knowing exactly what the rules guarantee about that bar, and what they do not.

The federal geometry

Covered trailers and semitrailers with a gross vehicle weight rating (GVWR) of 4,536 kg (10,000 lb as printed in the rule) or more, built on or after 26 January 1998, must carry a guard meeting Federal Motor Vehicle Safety Standard (FMVSS) No. 223, installed so the vehicle meets FMVSS No. 224. Paragraph (a)(1) excludes specified vehicle types, listed in the exception table. The dimensions in 49 CFR 393.86:

Other vehicles within 393.86(b)’s scope, built after 31 December 1952 and with the rear bottom edge more than 30 in above the ground when empty, follow the older set: guard bottom no more than 30 in above the ground, within 18 in of each side, no more than 24 in forward of the rear. 49 CFR 393.86(b)(1).

Source: 49 CFR 393.86(a)(1)–(a)(5), (b)(1)–(b)(3), current text verified September 2026. Paragraphs (a)(3) and (a)(4) permit specified rounded or curved ends within 255 mm (10 in) of the sides. Paragraph (b) also has exclusions and an equivalent-body/chassis-protection provision; the older dimensions are not universal.

No minimum ground clearance is specified in these clauses

The cited guard clauses cap how high a guard sits. They do not specify a minimum ground clearance. That does not create a legal range beginning at zero, and it does not prove that every lower guard position is compliant.

A restraint's published window might start at 9 inches. A guard sitting at 7 inches is below that endpoint. Whether the trailer is compliant and whether a particular device can engage it are separate checks.

Rite-Hite’s SHR-5100 product page describes a dual-articulating nose extension on its 9-inch carriage option for servicing rear impact guards lower than 22 inches. That is a named configuration feature, not a measurement of how common those guard heights are. Sources: 393.86(a)(3)–(a)(5) and SHR-5100 product page.

Inspection uses two vehicle groups—not a looser damage allowance

Since 9 December 2021, the rear impact guard is an item on the federal annual vehicle inspection. The pass/fail criteria are at Appendix A to 49 CFR Part 396, item 15 — and they come in two sets.

Sources: current Appendix A to 49 CFR Part 396, item 15 and 86 FR 62105, effective 9 December 2021. Verified September 2026. The table summarizes item 15; use its vehicle definitions and exclusions, not just a trailer’s age.

Two things fall out of this table that are worth having in front of you.

These are different covered vehicle groups. The 30-inch, 18-inch and 24-inch set is not a damage allowance for a trailer governed by item 15.a. A bent or repaired guard does not become compliant merely because it remains below a height limit: secure attachment and safe-condition requirements still apply. Sources: Appendix A, item 15 and 49 CFR 396.3(a)(1).

100 mm is written two ways in two federal documents. 49 CFR 393.86(a)(5) says “100 mm (3.94 inches).” Appendix A item 15.a.6 says “100 mm (4 inches).” Same millimetres, two rounded conversions. Blue Giant’s SVR303 page separately specifies 4 inches of minimum contact space. A guard’s cross-sectional height and a restraint’s contact-space requirement are different measurements; the rounding difference does not prove a compatibility gap. Sources: 393.86(a)(5), Appendix A, item 15.a.6 and SVR303 specifications.

The weight parentheticals also differ. Section 393.86(a)(1) prints 4,536 kg (10,000 pounds); Appendix A item 15.a prints 4,536 kg (10,001 pounds). The metric figure is the same. We preserve that source discrepancy rather than inventing a one-pound operating exception.

The direction the federal test does not cover

This is the finding most worth checking yourself, because it takes one clause.

FMVSS No. 223 sets guard strength and energy-absorption requirements. Under the current text:

• 50,000 N at test point P1 and 50,000 N at P2, without deflecting more than 125 mm or eliminating an existing load path.
• At least 350,000 N uniformly distributed across the horizontal member, with the same deflection and load-path conditions.
• For guards other than hydraulic guards and guards installed on tanker trailers, at least 20,000 J absorbed in the first 125 mm of distributed-load deflection, with the stated load-path and post-test 560 mm ground-clearance conditions. S5.2.2(b) provides an alternative for resistance greater than 700,000 N, while retaining the specified post-test clearance.

N is newtons, a force unit; J is joules, an energy unit. A load path is a route through the structure that carries the test force. These requirements concern guard certification, not a dock restraint’s advertised rating.

Source: 49 CFR 571.223, S5.2.1 and S5.2.2, current text verified September 2026. The applicable manufacture-date edition and transition provisions matter; the 15 July 2022 rule publication date is not itself a universal vehicle cutoff.

Now S6.6(a), which describes how the force is applied:

apply force to the guard in a forward direction

Forward. Toward the front of the trailer. That is the direction a car hits it in an underride crash, which is what the standard is for.

Holding back a trailer that is pulling away from the dock is a different load case. The force path depends on the restraint and its engagement; the FMVSS forward-load test is not a dock-restraint certification test.

We are not saying guards fail under restraint loads. We have no comparative failure data here. We are saying something narrower and checkable: S6.6(a) applies the guard test force forward; it does not establish a restraint’s holding capacity at the dock. Source: FMVSS No. 223, S6.6(a).

One aside on editions, because it trips people up. The P3 point load of 100,000 N and the 5,650 J energy requirement at P3 for non-hydraulic guards belong to the earlier version described in NHTSA’s 2022 rule background. The rule was published on 15 July 2022, became effective 11 January 2023, and set a 15 July 2024 compliance date, with optional early compliance. 49 CFR 393.86(a)(1) ties the requirement to the standards in effect when the vehicle was manufactured. Check the applicable edition and transition provisions before treating today’s values as an older guard’s original test requirements. Sources: 2022 final rule, DATES and background and 393.86(a)(1).

On 23 March 2026 the FMCSR requirement that a rear impact guard carry a permanent certification label was rescinded. The labelling duty FMVSS No. 223 places on guard manufacturers is untouched. If your inspection form still treats the removed FMCSR label provision as a current requirement, update that item—not the remaining guard-condition checks. Sources: 91 FR 7874 and FMVSS No. 223, S5.3.

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What 15 restraint models publish

Same columns, every brand in this selected sample. We put the published values and their limits side by side so you do not have to reconcile the documents yourself.

Sources: the issuer documents linked in each row; exact locators, editions and scope notes are in the restraint spec ledger. Verified September 2026. These are manufacturer-stated figures, not independent tests. “Not reported” means absent from the cited source; “not applicable” means a RIG-height column does not describe the wheel-dependent configuration. No common cross-brand test basis was established for these figures.

† RVR303 reach: the manual prints 14 in beside 381 mm. Those units conflict: ● 14 × 25.4 = 355.6 mm. We retain the printed inch figure, flag the inconsistency and do not use it to approve an installation. Confirm actual reach with the manufacturer. The HVR303 page separately gives a 9–26 in capture range and 16 in float; the calculated 17-inch endpoint span is not a replacement for its travel specification.

The Serco SLSC sheet specifies rear-axle position 32 in to 14 ft from the dock face, not a RIG-height window. It does not supply the unnamed distributor row’s 32,000 lb figure, so no such force appears here.

What the numbers say, once you line them up:

• ● 12 of 15 models contain a published force figure. Three do not in the cited sources.
• ● Four printed force numbers appear across five manufacturers: 30,000, 32,000, 35,000 and 40,000 lb. “Up to” and “in excess of” do not mean the same thing. We do not average them or treat the clustering as proof of a common test.
• ● 13 of 15 publish both vertical engagement endpoints. Lower endpoints run 7–12 inches; upper endpoints run 25–34 inches.
• ● Arithmetic spans run 14–27 inches, averaging 18.81 inches. Formula: high endpoint minus low endpoint; sum of the 13 spans, 244.5 in, divided by 13. This is an endpoint comparison, not measured travel or compatibility.
• ● 8 of 13 windows start at or below 9 inches. Five start above it.
• ● 8 of 13 windows end below 30 inches. That is a numerical comparison with the clearance figure in the older-vehicle rule, not a declaration that every older vehicle is covered or that a particular trailer will fail to engage.

Calculated results use the 15 source-linked records above and are reproduced by the build script. They describe this purposive documentation sample, not market shares or safety outcomes.

Two numbers on the same product

The Blue Giant RVR303 owner’s manual contains a wrinkle worth knowing about.

Page 4 states the unit applies 35,000 lb of restraining force.

Section 9.0 illustrates a serial plate carrying ANSI code MH30.3-2005 and TEST LOAD 22,500 lb.

Both figures come from Blue Giant, in the same document, dated 13 March 2026. The manual does not state a test method for the 35,000 lb figure. The illustrated plate labels one figure as a test load and separately prints an ANSI edition. That is not the test report or the text of the standard.

We are not saying either number is wrong. We are saying they have different labels and must not be treated as interchangeable. If you are comparing quotes, the sentence worth putting in an email is: what does the serial plate say, and against which edition of MH30.3?

For scale only: ● 22,500 lbf converts to 100.1 kN (formula: 22,500 × 4.448222 N/lbf ÷ 1,000; unrounded result 100.084995 kN). The federal point-load requirement for the guard itself is 50 kN at P1 and P2. Those are different tests, and we are not presenting the conversion as a performance comparison. Sources: RVR303 manual, p.4 and §9.0, NIST SP 811 conversion table and FMVSS No. 223.

One brochure claim worth checking

Pentalift’s specification sheet names MFRSA32 and describes its 10.5-inch-to-28.5-inch operating range as one that “accommodates all legal trailer heights.” The filename includes MFRAL, but that does not establish a second interchangeable model. Source: Pentalift specification, p.2.

The federal clauses do not define a legal interval from zero to 22 inches. A 10.5-to-28.5-inch window does not include a 9-inch or 30-inch guard position, but those numbers alone do not establish the vehicle’s legal status or its full compatibility. The brochure’s broad wording is not a substitute for a dock-and-trailer application check.

We raise it because it is checkable and because the same caution applies to every brochure in the table, this publication included: the window is a specification, and the trailer at your dock either falls inside it or does not.

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Where a restraint can't engage: 18 conditions

This is the table to print and keep. Seven rows are vehicle categories excluded from the particular guard requirement in 393.86(a)(1). The rest are scope, geometry, condition and site questions. None is permission to load an unsecured trailer.

Sources: issuer links in each row, including 393.86, 393.41, Appendix A to Part 396 and named-model manufacturer documents. The exception ledger preserves additional sources and exact locators. Verified September 2026. The engagement implications are Uptime’s source-grounded synthesis, not agency-issued compatibility verdicts.

This is the operational reason to document what happens when a restraint cannot engage. An alternative may involve suitable chocks or a wheel-dependent device, but it must follow the actual equipment and site procedures—not an improvised substitute.

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What the manufacturers say about keeping chocks

The restraint manufacturers’ own instructions matter to the chock decision. They do not all give one universal answer.

We read the Blue Giant StrongArm RVR303 Owner’s Manual, part 038-953E, Rev.1.8, issued 13 March 2026, and the Rite-Hite GWC-1000 and SHR-5100 product pages. The downloadable ledger contains fourteen instruction and application records from those three documents. These six RVR303 instructions bear directly on the chock decision.

Source: Blue Giant RVR303 Owner’s Manual 038-953E, Rev.1.8, 13 March 2026, §§2.4, 3.1, 6.1, 6.8 and 7.4. Verified September 2026. Short quotations and paraphrases do not replace the full model-specific instructions; no operating placards, diagrams or override sequence are reproduced.

That is one manufacturer's manual for one model range. It is not every restraint on the market. It is public, and it shows why removing chocks is an equipment-specific decision.

The manual also carries the design assumption that everything above depends on: the restraint is designed for rear impact guards that follow FMVSS Nos. 223 and 224. A guard outside that envelope is outside the design assumption.

Does a green light mean it's secure?

Not by itself. You need to know what the exact control system senses and what its indication means.

The same manual's troubleshooting section lists this fault outright: restraint hook does not hold ICC bar tightly, inside lights turn green.

The manufacturer documents that fault for this model. A light is a status indication from a sensor and a controller; this example is not a rule that every green light measures—or fails to measure—the same thing. Source: RVR303 manual, §12 troubleshooting, p.32.

That is not an argument against light systems — feedback is a useful difference from a bare, unmonitored chock. It is an argument for knowing what your specific controller senses, what it displays when the sense is lost, and who confirms it before anyone drives into the trailer.

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What a chock rating actually means

Sources: the six Checkers/Justrite issuer product pages linked in the model column, verified September 2026. Ratings describe the named product and conditions, not measured holding force. “Not stated” is a source limitation, not unlimited capability. The chock ledger also contains six selected gross-weight bands from the manufacturer’s 2025 reference guide; those six bands are not six more products or the guide’s complete chart.

The MC3009 page separately lists 70-ton payload capacity; the MC3011 page lists 400-ton payload capacity. Those are payload statements, not conversions of 245,000 lb and 1,600,000 lb gross vehicle operating weight. For the MC3011’s 855,000–1,600,000 lb range, the page specifies a minimum of four chocks.

Three things to take from this table.

The rating is a vehicle weight, not a grip. "60,000 lb" means the maker rates the chock for vehicles up to that gross operating weight, matched to a tire diameter. It does not mean the chock resists 60,000 lb of pull.

Where a grade limit is published, read it. One model is rated to 20,000 lb on slopes up to 11 percent. Most of the six product pages in this table state no grade limit, which is not the same as no limit existing.

A product listing may omit the weight rating. The RC815 listing we read gives size, material and application—but no weight rating. If a chock is the thing standing between a forklift operator and a moving trailer, "we bought it from the catalogue" is not a specification.

And the selection inputs matter more than the badge. Checkers' own selector asks for vehicle weight, tire diameter and traction conditions. Those are selection inputs, not a complete approval of the bay. Check the named-model instructions, quantity and application conditions as well. Sources: Checkers selector and 2025 reference guide; the guide’s chart test basis is an 8% grade, not a universal limit for every product.

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How to choose

Four questions, in order. Each answer comes from something verified above; the recommendations are our editorial judgment, and we say so.

1. What actually backs into your bays? Run your fleet mix against the 18 conditions. If liftgate vehicles, parcel trucks, intermodal chassis or older units are a regular part of your traffic, check them against the exact RIG restraint rather than assuming they all fit—or all fail to fit. That is not a reason to skip the restraint. It is a reason to plan what happens on the trailers it cannot hold, before it happens.

2. What is the approach like? Slope, drainage, ice, oil, gravel. Record the actual approach and compare it with the chock’s instructions and the restraint’s application survey. A grade rating does not certify every traction condition. The parking-brake rule’s ice-and-snow wording is a performance condition, not a shortcut to deciding jurisdiction.

3. Who is present when the trailer is secured, and what tells them? A loose chock says nothing to anyone. A monitored device — restraint or chock — drives lights the driver and the forklift operator can see. If your process depends on a person remembering, and a second person trusting that they did, the device is only half the system. A person setting a chock enters the drive approach, so the procedure must manage vehicle movement and safe access.

4. Can you meet all three directive conditions, continuously? Effective movement prevention. Installed, maintained and used as the manufacturer recommends. Damaged equipment removed from service immediately. Condition two has a schedule attached — one manufacturer's is quarterly, or monthly on multi-shift. If you cannot show that schedule is being kept, the strongest argument for retiring your chocks gets weaker.

Basis: OSHA STD 01-11-007, 2011 host-employer interpretation, 2011 State Plan interpretation, and the source-linked manufacturer/exception tables above. This is a documentation framework, not loading permission or a product recommendation.

We do not publish prices. The reviewed sources do not establish a comparable installed-cost range for these configurations, so we do not invent one. What we can tell you is what to make a quote include: the dock survey, the named model and configuration, the installation work, controls and integration, commissioning and training, the maintenance schedule, and what happens when a trailer arrives that the device cannot engage.

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Keeping either one working

When relying on OSHA’s mechanical-restraint alternative, condition two requires manufacturer-compliant installation, maintenance and use; condition three requires damaged equipment to be removed from service immediately. Chocks also need to meet their own product instructions.

What to look at, as observation:

• Do the lights agree with what the hook is doing?
• During normal authorized operation, does the restraint deploy and store as its instructions describe? Do not cycle it just to investigate a fault.
• Are chocks cracked, worn smooth, or simply missing from the rack?
• Is the driveway shedding water where the unit mounts, or standing it?

Stop loading and resolve the securement problem before anyone enters the trailer:

• A restraint fault, damaged mechanism or indication that does not agree with its approved operating state
• No usable guard for the selected RIG restraint, including damage or insecure attachment
• A damaged chock or one that moves rather than seating as its instructions require

A vehicle without a RIG is not automatically illegal. It still needs a compatible, approved securement arrangement. Damaged equipment stays out of service; a non-engaging arrival needs an assessed alternative, not an improvised override.

What we will not tell you how to do. This page gives no repair procedure, no adjustment values, no bypass or override sequence. Powered restraints can contain stored energy, hydraulics and electrical systems. The cited RVR303 manual restricts installation, repair and adjustment to trained and authorized personnel. The right move is: observe from a safe position, stop the affected operation, secure the area under the site procedure, and involve someone qualified. Sources: RVR303 manual, safety and maintenance sections and STD 01-11-007.

A damaged or malfunctioning restraint needs qualified assessment; an incompatible trailer may need a different securement arrangement rather than a repair. Uptime’s loading-dock repair service guide explains the service-request categories. If the problem is the leveler bridging the gap rather than the device holding the trailer, our dock leveler troubleshooting reference covers that side.

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What we could not confirm

1. This is not legal or compliance advice. We point to the primary sources so you can check them against your own facts.
2. OSHA letters of interpretation explain requirements; they cannot create new obligations, and OSHA revises its guidance. The applicable issuer guidance and current regulation must be read together.
3. Manufacturer figures are manufacturer-stated, for the named model and document edition we read. They are not independent testing. We did not establish a common test basis across the selected figures, and the source wording and qualifiers are retained rather than converted into a performance comparison.
4. Fifteen restraint models and six chock products are not the whole market. This is a documented sample, chosen because the specifications are publicly published. The sample is not random. One row uses a historical 2015 issuer release and does not claim current availability.
5. We read one state's rule, not fifty. State plans must be at least as effective as federal OSHA and several write their own text. Check yours.
6. How a state-plan state applies the commercial-vehicle preemption argument is not settled here. OSHA's own 2011 letter says the matter must be resolved under state law.
7. ANSI MH30.3 and SAE J348 are consensus standards sold by their publishers, not automatically applicable laws. We report scope, definitions, clause headings and edition history from ANSI's published preview and the publishers' listings. We did not buy either standard and we do not paraphrase clause text we have not read.
8. Online availability is not the same as current applicability. We read the 1981 directive with OSHA’s published loading/unloading resource and its later interpretations. An older instruction or letter is not a stand-alone compliance determination for a particular employer, vehicle or State Plan.
9. There is no accident or injury data on this page. Not because it does not exist, but because a comparison of published equipment ratings is a different job, and mixing the two invites exactly the kind of unsourced percentage this page was built to avoid.

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How we built this

What we did. We checked issuer-published material—federal regulations, OSHA directives and interpretations, California’s rule, public standards previews/listings, and manufacturer documents—on 17 September 2026. Some historical events are verified through later issuer histories, as identified in the records. We recorded each consequential claim with its citation, edition and verification date, then assembled 108 records in six data tables. The 30 authority records are not a count of distinct sources.

How rows were joined. The restraint spec ledger uses identical columns across the selected brands so the documented inputs can be inspected side by side. Matching columns do not create a common test basis. The primary key is the record ID; for timeline records it is seq. Source URL, locator, edition, verification date and scope travel with each record. Blank CSV fields become JSON null; context distinguishes “not stated in this source” from “not applicable to this configuration.” Neither means zero.

How derived figures were computed. Every ● figure is reproduced by the build script shipped with the dataset. Span is the published high endpoint minus the published low endpoint. The mean span uses the 13 rows with both endpoints: 244.5 ÷ 13 = 18.81 in, rounded to two decimals. Counts and endpoint ranges use those same named records. There is no mean force and no computed legal low-height band. The load conversion uses NIST’s published 4.448222 N/lbf factor; the reach unit check uses 25.4 mm/in. The Serco axle-position conversion is 14 ft × 12 = 168 in, a different variable from RIG engagement height.

What ★ and ● mean. ★ Source-reported: checked in the cited primary source. ● Calculated: computed here from cited inputs, with the formula shown. Both are verified and publishable. Selection questions and “why it matters” columns are Uptime’s editorial synthesis, not agency or manufacturer findings.

What we deliberately left out. Installed-cost comparisons, because the sources do not establish a like-for-like scope. Accident and injury statistics, because that is a different search and a different evidence standard. Any figure that circulates without a traceable origin. Any clause text from a standard we did not read. Any repair, adjustment or override procedure.

What this is not. Not independent product testing. Not a field audit. Not a manufacturer census. Not a compliance determination for any facility.

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Sources

The source-linked rows and downloadable source manifest identify the document, supporting location, source edition and 17 September 2026 verification date. The date of verification is not the date of the underlying rule or manual.

Federal regulations and enforcement material

• 29 CFR 1910.178 — powered industrial trucks; (k)(1)–(k)(4), (m)(7), training provisions
• 29 CFR 1910.26(d) — dockboard movement prevention
• 29 CFR 1910.21(b) — dockboard definition
• 49 CFR 393.86 — rear impact guards and rear-end protection
• 49 CFR 393.41 — parking-brake requirements and specified chocking-block cases
• 49 CFR 571.223 — FMVSS No. 223, strength, energy, labelling and test direction
• Appendix A to 49 CFR Part 396, item 15 — rear-guard inspection criteria
• 49 CFR 396.3 — safe and proper equipment condition
• 49 CFR 396.17 — periodic inspection
• OSHA STD 01-11-007, 5 August 1981 — mechanical-restraint alternative, F.1–F.3
• OSHA powered-industrial-truck loading/unloading resource
• OSHA interpretation, 9 February 1996 — effective rear-wheel chocking
• OSHA interpretation, 14 September 2005 — alternative movement-prevention systems
• OSHA interpretation, 8 November 2005 — CMV preemption; also discussed in the 2011 letter
• OSHA interpretation, 7 March 2011 — history, withdrawals, host employers and training
• OSHA interpretation, 14 June 2011 — State Plan jurisdiction
• OSHA directive index — CPL 02-01-030 date
• OSHA State Plans directory — current coverage
• OSHA product-approval guidance
• California 8 CCR 3650(j), (t)(22), (t)(23) — support, highway trucks and rail situations

Rule changes, public standard material and conversions

• 87 FR 42339, 15 July 2022 — guard-test changes, previous requirements, effective date and compliance date.
• U.S. Department of Labor, Employment Law Guide — de minimis violations.
• 86 FR 62105, 9 November 2021; effective 9 December 2021 — rear-guard annual inspection and rule history
• 91 FR 7874, 19 February 2026; effective 23 March 2026 — FMCSR label-requirement rescission
• ANSI MH30.3-2015 — public preview only
• MHI/LODEM — public scope and edition listing
• ANSI MH30.3-2022 — publisher listing, not the paid text
• SAE J348_202010 — publisher listing; stabilized 19 October 2020, last revised 26 June 1990
• NIST SP 811, Appendix B.9 — force conversion

Manufacturer documents

• Blue Giant StrongArm RVR303 — StrongArm RVR303 Owner's Manual 038-953E Rev.1.8. 13 March 2026.
• Blue Giant StrongArm SVR303 — StrongArm SVR303 product page. Undated issuer product page, verified 2026-09-17.
• Blue Giant StrongArm TL85 — StrongArm TL85 product page. Undated issuer product page, verified 2026-09-17.
• Blue Giant StrongArm HVR303 — StrongArm HVR303 product page. Undated issuer product page, verified 2026-09-17.
• Blue Giant StrongArm ML10 — StrongArm ML10 product page. Undated issuer product page, verified 2026-09-17.
• Rite-Hite Dok-Lok VBR-100 — VBR-100 product page. Undated issuer product page, verified 2026-09-17.
• Rite-Hite Dok-Lok SHR-5000 — Rite-Hite issuer news release for SHR-5000. 2015; historical source.
• Rite-Hite Dok-Lok SHR-5100 — SHR-5100 product page. Undated issuer product page, verified 2026-09-17.
• Rite-Hite GWC-1000 Global Wheel Chock — GWC-1000 Global Wheel Chock product page. Undated issuer product page, verified 2026-09-17.
• Pentalift RVR32 — RVR32 brochure, footer 0121D050. Footer 0121D050; no publication date inferred from URL.
• Pentalift MFRSA32 — MFRAL-Spec.pdf: sheet names model MFRSA32. Undated specification.
• Pentalift UHR40 — UHR40 specification (UHRSpec.pdf). Undated specification.
• Poweramp PowerHook — PowerHook manufacturer product page. Undated issuer product page, verified 2026-09-17.
• Poweramp PowerStop (AAL) — PowerStop AAL manufacturer product page. Undated issuer product page, verified 2026-09-17.
• Serco SLSC SAFETY-CHOCK — SAFETY-CHOCK Wheel Restraint Product Specifications. Form SPS-VWSM-0725.
• Checkers UCTS003 product page. Product values and conditions verified 17 September 2026.
• Checkers UC1400-6 product page. Product values and conditions verified 17 September 2026.
• Checkers UC1700 product page. Product values and conditions verified 17 September 2026.
• Checkers MC3009 product page. Product values and conditions verified 17 September 2026.
• Checkers MC3011 product page. Product values and conditions verified 17 September 2026.
• Checkers RC815 product page. Product values and conditions verified 17 September 2026.
• Checkers Wheel Chock Reference Guide, CK407r1-guide(0325), copyright 2025 — six selected weight-band records, not a reproduction of the full guide.
• Checkers wheel-chock selector — vehicle, tire and traction inputs.

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How to cite this page

Uptime Dock & Door Research. "Vehicle Restraints vs Wheel Chocks: What Each One Holds, and What OSHA Actually Requires." Includes the Trailer Securement Ledger, data edition 1.2.0. Last verified 17 September 2026. Canonical page.

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Download the data

The Trailer Securement Ledger, data edition 1.2.0. 108 rows across six tables, compiled September 2026. Free, no sign-up.

Data dictionary. published_restraining_force_lb is the manufacturer-stated force number for the named model; retain force_qualifier and force_wording_as_published. vertical_window_low_in and vertical_window_high_in are published guard-height endpoints. vertical_window_span_in is their calculated difference—not measured travel or a legal height range. gross_vehicle_operating_weight_lb describes a chock’s vehicle-weight rating, not holding force. payload_capacity_as_reported is a separate cargo-capacity statement. The complete dictionary covers every field.

Missing values. Empty CSV fields become JSON null. Read record_type, device_family and scope_note to distinguish not stated from not applicable. Unknown is not zero; a missing rating is not unlimited capacity.

Reuse. The files contain Uptime’s original selection, short factual paraphrases and editorial analysis. Third-party manuals and standards remain subject to their owners’ rights. No new open licence is assigned to that third-party material, and the downloads do not reproduce protected manuals, diagrams or the complete Checkers selection chart. Suggested citation is optional, not a condition of downloading the files.

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Questions people ask

If we install restraints, can we throw the chocks away? Not on the evidence here. OSHA's directive lets a restraint stand in for chocks on three conditions, and one restraint manufacturer's current manual tells owners to review the need for chocks alongside the restraint and states that chocks are necessary when the restraint is bypassed. Plan for any trailer the selected restraint cannot engage. Keep the equipment required by the approved alternative, and follow the exact manufacturer and site procedure.

Is a dock lock "OSHA approved"? No such thing exists. OSHA does not approve dock equipment. What exists is a 1981 enforcement directive saying OSHA will not cite you for skipping chocks when a positive mechanical restraint meets three conditions.

Whose job is it to chock — ours or the driver's? The regulations place duties on employers to protect their own workers. OSHA's 2011 letter is explicit that a powered industrial truck operator must be trained not to drive onto a trailer at the dock unless it is secured or restricted from movement first. Whose hands place the chock is a site procedure question; whose duty it is to make sure it happened before your forklift enters is not.

What do we do with a trailer that has no usable rear impact guard? Stop loading until a compatible securement arrangement has been established under the equipment and site procedures. The RVR303 manual requires manual chocking before loading when its approved bypass provision is used; that is a model-specific condition, not a universal instruction to override a restraint. A wheel-dependent device may be another assessed option.

Does a restraint stop trailer creep, or only early departure? ANSI MH30.3 defines a vehicle restraining device as intended to limit vehicle creep and prevent unscheduled departure. Both are in the scope of the standard.

Do we need anything extra for a trailer parked without its tractor? Possibly. Both 29 CFR 1910.178(k)(3) and (m)(7) say fixed jacks may be necessary to support a semitrailer and prevent it up-ending during loading when it is not coupled to a tractor. California's 8 CCR 3650(j) says disconnected trailers must be secured against up-ending. That is a separate support question; do not assume a movement-prevention device settles it.

Does OSHA specify one chock or two? OSHA’s 9 February 1996 interpretation says enough rear-wheel chocks must be used to effectively prevent unintended movement. It does not give this page a universal one-or-two answer. The named chock’s instructions and application conditions still matter. Read the interpretation.

Which is cheaper? The evidence here does not establish a like-for-like installed-price comparison. We will not print an invented range. The costs that actually separate them are the dock survey, installation, controls, training, maintenance and what happens on the trailers the device cannot hold.

Sources for the regulatory and equipment answers: STD 01-11-007, OSHA’s 2011 interpretation, 1910.178(k)(3), (m)(7), California 3650(j), MH30.3 public scope and RVR303 manual. Cost-scope questions are editorial, not price estimates.

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Uptime Dock & Door Research publishes source-based reference material for people who work around loading docks and commercial doors. Uptime Dock & Door is a commercial service-referral publisher, not a repair contractor. We have no affiliation with any agency, standards body or manufacturer named on this page.

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