During a training exercise in March 2021, a Soldier suffered a serious foot injury while disconnecting a full M149 water trailer from the prime mover. The Soldier’s foot was fractured. I’d like to share the two (2) mistakes that my unit found which caused the mishap: the wrong adjustable caster assembly (landing leg) and lack of good PMCS of the locking pins.
We found that the trailer was outfitted with a non-adjustable caster assembly (landing leg), which was designed for a lighter trailer like the M105, but never designed for a heavy trailer like the M149.
Non-adjustable caster is wrong landing leg
The correct landing leg for the M149 water trailer is the adjustable caster assembly, NSN 2590-01-183-6816.
Use M149 adjustable caster landing leg
The other issue was lack of proper PMCS of the landing leg locking pins. The pins were rusty and hard to properly seat, unless they were forced into position with a hammer. This led to the locking pins not being fully inserted which resulted in their failure, causing the trailer landing leg to collapse. Proper maintenance requires cleaning and lubricating the locking pins for smooth operation as outlined in TM 9-2330-267-13&P (Dec 15).
It’s also recommended to use a paint marker or nail polish to draw a witness mark that indicates when the locking pins are properly in the locked position.
Draw witness mark on locking pins
Brigade Safety Manager
Editor’s note: Mr. Zacheus, we appreciate you sharing this information with us. And just in case anyone missed it, in 2002, the TACOM Safety Office issued Ground Precautionary Message (GPM) 02-20 advising that the mounting mechanism for the landing leg/caster used on many light trailers can fail if improperly used.
Here’s a copy of GPM 02-20:
Click on image above to open and view PDF