How many tiedowns does a flatbed load need?
Two things must both be true: the combined working load limit of your tiedowns must be at least half the cargo's weight, and you need a minimum number of tiedowns based on each article's length and weight. For an article over 10 feet that is not blocked at the front, that is two tiedowns for the first 10 feet plus one for each additional 10 feet or part of it. Check FMCSA's cargo securement rules for the details and commodity-specific requirements.
Flatbed cargo securement is where flatbed drivers earn their pay and protect their record. The federal rules are in 49 CFR 393.100 through 393.136, and inspectors check them closely. This guide covers the core math, the commodity rules you need to know, and a checklist you can use on every load.
The performance standard behind the rules
The securement system as a whole must be strong enough to hold the cargo against set forces. In plain terms, it must keep the load from moving under:
- 0.8 g forward deceleration (hard braking)
- 0.5 g rearward acceleration
- 0.5 g sideways (lateral) force
- Enough downward force to prevent vertical movement when the cargo is not otherwise fully contained
You do not need to calculate g-forces on every load. The tiedown and working load limit rules below are designed to meet these standards for typical freight.
Rule 1: working load limit (WLL)
Every tiedown has a working load limit, which should be marked on the strap, chain or binder by the manufacturer. The rule:
The aggregate WLL of all tiedowns must be at least 50% of the weight of the cargo.
How each tiedown counts:
- Indirect tiedown (trailer, over or through the cargo, back to the trailer): counts its full WLL.
- Direct tiedown (trailer straight to an attachment point on the cargo): counts half its WLL.
- The weakest component sets the WLL. A strong chain with a weak binder or hook is only as strong as the binder or hook.
Rule 2: minimum number of tiedowns
Separately from WLL, each article needs a minimum number of tiedowns based on its length and weight. If the article is not blocked at the front by a headboard or another article:
| Article | Minimum tiedowns |
|---|---|
| 5 ft or shorter and 1,100 lbs or less | 1 |
| 5 ft or shorter and over 1,100 lbs | 2 |
| Longer than 5 ft, up to 10 ft | 2 |
| Longer than 10 ft | 2, plus 1 for each additional 10 ft or part of 10 ft |
If the article is blocked against forward movement by a headboard, bulkhead or other cargo that is itself secured, the minimum is generally one tiedown for each 10 ft of length or part of it.
You must satisfy both rules. Plenty of loads meet the WLL with three heavy chains but still need more tiedowns because of their length.
Worked example
Hypothetical load: three bundles of steel tubing, each 20 ft long and 12,000 lbs, for 36,000 lbs total, loaded side by side and not blocked by the headboard.
Count per bundle: 20 ft is longer than 10 ft, so 2 for the first 10 ft plus 1 for the next 10 ft = 3 tiedowns per bundle, or 9 total.
WLL: half of 36,000 lbs is 18,000 lbs. If you use straps over the top (indirect) each marked with a WLL of 5,000 lbs, nine straps give 45,000 lbs of aggregate WLL. That clears 18,000 lbs comfortably.
Both rules are met. If the bundles were blocked against the headboard, the minimum count would drop to 2 per bundle, but most drivers still add extra straps for real-world safety margin.
Commodity-specific rules
Some cargo has its own section in the regulations, and those rules apply on top of (or instead of) the general rules. The main ones:
- Logs
- Dressed lumber and similar building products
- Metal coils (different rules for eyes vertical, eyes crosswise and eyes lengthwise)
- Paper rolls
- Concrete pipe
- Intermodal containers
- Automobiles, light trucks and vans
- Heavy vehicles, equipment and machinery (for example, items over 10,000 lbs generally need at least four tiedowns, with accessories like blades and buckets lowered and secured)
- Flattened or crushed vehicles
- Roll-on/roll-off and hook-lift containers
- Large boulders
If you haul any of these regularly, read that section of the regulations and FMCSA's driver's handbook on cargo securement until you know it well. Metal coils and heavy machinery are the two that trip up new flatbedders most often.
Condition of your gear
Securement violations are often about worn equipment, not the number of straps. Inspectors look for:
- Cuts, tears, burns or broken stitching on straps
- Knots in straps or chains
- Cracked, stretched or damaged chain links, hooks and binders
- Missing WLL markings
- No edge protection where a strap crosses a sharp edge
Use edge protectors on any sharp or abrasive edge. Retire damaged gear right away; it is cheaper than an out-of-service order. Our guide on out-of-service criteria explains what can sideline a truck.
When to re-check
Under the driver inspection rule:
- Inspect cargo and securement before the trip.
- Re-check within the first 50 miles and adjust as needed.
- Re-check when your duty status changes, or after 3 hours or 150 miles of driving, whichever comes first.
Straps loosen as loads settle and as temperatures change, especially with lumber and tarped loads. Build these stops into your trip plan so they do not eat into your hours unexpectedly. Add them to your pre-trip inspection checklist.
Overhang and wide loads
- Cargo extending more than 4 ft beyond the rear (or projecting beyond the sides) must be marked with red or orange warning flags, and with lights when lamps are required.
- Anything wider than legal width or taller than the state's height limit needs a permit. See oversize and overweight permits.
Pre-departure securement checklist
- Weight of each article known and written down
- Tiedown count meets the length rule for each article
- Aggregate WLL is at least half the cargo weight
- All gear marked with WLL and in good condition
- Edge protection on sharp edges
- Commodity-specific rules checked if they apply
- Loose items, dunnage and tarps secured
- Overhang flagged; permits on board if oversize
- Re-check stops planned at 50 miles and every 3 hours or 150 miles
Rules can be updated and interpretations vary. Confirm current requirements with FMCSA and the CVSA out-of-service criteria, and follow any stricter shipper instructions.
How Texas Solutions can help
Texas Solutions is a dispatch service, not a broker or a motor carrier. Our flatbed dispatch team finds and negotiates loads that match your trailer and securement gear, handles broker packets and paperwork 24/7, and you approve every load. You can also talk to a dispatcher.
Frequently asked questions
How often do I have to check my securement?
Within the first 50 miles of a trip, and then whenever your duty status changes or after 3 hours or 150 miles of driving, whichever comes first. Re-tighten anything that has loosened.
Does a direct tiedown count the same as one that goes over the load?
No. A tiedown that runs from the trailer over or through the cargo and back to the trailer counts its full working load limit. One that runs from the trailer straight to an attachment point on the cargo counts only half.
What if my strap or chain has no WLL marking?
The rules assign a default working load limit to unmarked tiedowns, which is usually lower than the rated value. Buying marked, rated gear makes your math easier and your inspections smoother.
Do I need to tarp every flatbed load?
Tarping is usually a shipper or broker requirement to protect the freight, not a securement rule. Tarps never replace tiedowns, and they must be secured so they do not flap loose.
