I was following a Waitrose Ocado doubledeck trailer through South West London today, and to my untrained eye, it didn’t look the most stable thing I’ve ever seen? The lean on it was quite alarming as it went round some tight roundabouts.
Do these type of trailers ever go over? Do they have to be loaded in a certain way to maintain centre of gravity? How do you even wash them? is it a special truck wash, or just a bloke with a ‘very’ long handled brush?
They don’t look like the most stable things, no. There are two of us pull them out of our depot at night, and I occasionally follow the other driver out of the yard. The lean on his trailer at the first roundabout is positively alarming, and I suppose my trailer must be doing the same. But they’re more stable than they look, as long as they’re loaded and driven sensibly. Don’t stick heavy stuff up the top (and keep an eye on the forklift drivers, who are not above sticking a ton pallet of welding wire on the top deck) and don’t hammer round roundabouts and they’re fine. As for washing them, we never bother. 
citycat:
Do these type of trailers ever go over?
No, They have big magnets in the trailer deck to prevent that happening.
Some of these double deck trailers have something called “tilt brakes” (no doubt there is a more correct name) which automatically apply when tilting has reached a certain degree.
I have myself only experienced this working when I’ve been turning in a sloping yard.
I used to drag one around and never had a problem with it even in high winds it was always stable. I don’t know what it looked like though. Every body was amazed when I washed it, they even came out of the office to see the result. Apparently it was the first time it had been washed. I didn’t have anything to do for an hour and thought it looked a mess.
I pull a decker around every day and I honestly don’t have any problems with stability. Yes they do lean a bit more on roundabouts, but as long as its loaded properly, they are fine. Even in strong winds, they are no worse than a straight framed trailer.
They must have some clever engineering behind them otherwise they’re the biggest heaps of zb I’ve ever had the displeasure of working with…!
Pulled them for over a year on night trunks, never had a problem with them in the wind or when cornering.
Wash them? Hahahaha. The state of most double deck trailers should suggest they don’t get washed very often. Ours don’t at any rate.
As others have said they are more stable than you’d think. As long as you’re sensible you can still press on without worrying. Bridges and low branches are more of a concern. Wind can be scary, all ours are curtained and when a strong gust hits you can certainly feel it. If they tilt as much as the others are saying its no wonder cars seem to hang back a bit more than normal around some bendy A roads lol.
Hiya…they must be more stable than a car transporter with only the top deck full of cars.
i served my apprenticeship as a panelbeater/bodybuilder, i can tell you the trailers have a very
strict testing on banked roads at MIRA test track on the A5 nr Nuneaton/ Hinckley.their are a number
of guidlines for manufactuing. you don’t just build one and operate with them.
Don Bur come up with a new idea for a trailer. it must have done 100,000kliks
just been tested.
John
The ones I’ve pulled at our favourite blue supermarket, due to be design layout of the fridges there’s actually more cages loaded on the top deck than the bottom, more often than not it’s fresh/chilled on the bottom and ambient and frozen (usually the heavier stuff) on the top. I’ve always been extra careful but there are other drivers who can go round a sweeping bend on a slip road with a double decker quicker than I can with a single. The are stable but I wouldn’t push my luck.
Our race trucks are always quite top heavy partly due to design layout… I’d say its solid as a rock and as a solid side trailer in wind it’s no different to a normal curtain sider.
And a 16’ pole and pressure washer to clean!
I’ve always found the tandem axle stepframe box variety that some retailers had but, seem to have all but disappeared now fairly iffy. Tri-axle nowhere near as bad so guess the weight of the extra axle has a lot of benefit.
The box van sort are worse as well as they often don’t have a full length chassis so have much less weight to them lower down and much more higher up in comparison to a curtainsider.
They’re not much fun to drive empty in a high crosswind. They may be as stable as a straightframe, but the psychological effect of that huge expanse of curtain makes me a bit twitchy every time I cross a motorway bridge. I’ve never been seriously close to blowing over though.