Been driving these recently, the ones that don’t lock off. 50ft long, crazy as fudge
I’ve never driven ones that lock off.
I find them quite good.
Follows the corners quite nicely.
adam277:
I’ve never driven ones that lock off.
I find them quite good.
Follows the corners quite nicely.
Yeah they’re great going forwards 
Most of ours lock when you put it in reverse as long as your wheels are straight.
Some are permanent steer though and it’s pretty tricky backing them in
I’ve driven the royal mail ones 110 york trailers, never had an issue with them as I’ve basically ignored the back axle and reversed then as if they only have the front two with a large overhang.
Can require a couple of shunts to get into a tight loading bay though… have heard other drivers taking out the cab of unit parked next to them though…
There are a few different types of rear steer trailers.
Ones where only 1 axle steers, and locks off when reverse is selected. That’s passive steering. The wheels only have a max steering angle of about 20/25° from straight ahead. They are a useful bit of kit
On the fleet of extending flatbeds we have, these make up the majority of the trailers. They pull and turn well to about 20mtrs.
Active rear steer.
This is done with the king pin has a wedge behind it that fits in to the V of the 5th wheel and is mounted on a swivel.
The rear axles are mounted on swivels like on A frame drawbar trailers.
The axles and kingpin are connected by a bar or cables. These are normally used on fixed length trailers, such as the longer trail trailers, or short urban trailers. These generally can’t be locked off. The easiest way I find to treat them is to imagine the trailer axles are at the middle of the trailer.
The other way these are operated is by hydraulics. These are way more complicated that the rod/cable method. We have triple and double extender that go to 70ft long
Due to the nature of them we can override the steering. And remotely steer it as seen in alleys train truckers.
When shut up we can lock the steering off but you end up dragging it around corners.
Having driven both up to 20mtrs a passive rear steer is a good tool for the job, over 20mtrs an active rear steer is better.
But access is key. A shorter load with an active rear steer can with the right driver and steersman get it in to some really tight places.