Hauling your gear to a launch: Testing Ratchet Straps

[Johnly]

Ratchet straps are ubiquitous at rocket launches, from keeping your pop-up canopies from blowing away during a dust devil to securing your gear on the drive to the launch site. I came across this testing video that evaluates conditions that could decrease the strength of straps in normal use, and thought others might find it interesting.

 

[0011001100]

Absolutely loved this video. Really shows just how strong they can be.

 

[rharshberger]

Ratchet straps are rated as the WLL ( working load limit) is 1/3 the breaking strength, what I found interesting was that the strap with a single twist aka had a higher breaking strength than the strap with no twist, this may be due to inconsistencies in the testing method. Straps are also rated as listed on the information tag, in its absence or illegibility the rating of the straps WLL falls to 1000lbs/inch of width so a 2" strap goes from 3333lbs to 2000lbs. This holds true for all straps used in load securement.....BBBUUUTT......1" straps are highly variable in their ratings, the ones from HF can be from 400 to 700ish lbs, other brands sold by other big box hardware places are similar in capabilities, there are 1" straps rated at 1500lbs. The strength of the 1" straps usually wont be questioned by Law Enforcement during a vehicle inspection but if there is fatality accident and the driver of the load is found at fault then the straps will be closely scrutinized and the driver may be charged with a misdemeanor or felony (look up Maria' Law a WA state law emulated in most US states). I teach load securement classes (about 5 to 6 four hour classes per month) at the US Dept of Energy's HAMMER training facility. Load Securement Laws apply to everyone not just the commecial drivers......

Performance Criteria for load securement states that the load shall be secured during normal driving conditions and during emergency maneuvers up to but short of a crash. Forces in a crash are far higher than standard loadcsecurement devices can handle.

 

[dhbarr]

I live in a part of the country where random dudes roll around with heavy objects sort of heaped on their flatbeds. At least it helps me remember not to follow too closely.