Does sliding the trailer tandem to the rear (for dock purposes) damage it?

I would say the opposite. You want the tandems as far back as possible so fork trucks coming off ramps and bouncing a bit will be bouncing directly on top of the tandems.

Fork trucks can be enormously heavy, especially in a warehouse with very high stacks, since the fork trucks need enough mass to counterbalance 1 ton pallets 30 feet in the air. A four ton fork truck carrying a 1 ton pallet and falling an inche off a ramp is a LOT of force. Bouncing back onto the ramp again might be even worse, even with no pallet.

 

Its sort of duh. Does it need mentioning?

Im not trying to pick a mess... many a time the trailers had wherever the tandems were on the tractor and when they slammed onto it its a wake up call. Grab your paper and get ready to count freight.

 

I was responding to the OP who was wondering if a sort of compromise distance to slide the tandems was possible in order to protect the trailer structure. At least, that's how I understood the question. My response was geared toward the obvious center of gravity advantages that fully rearward tandems would offer to the the safety of the loaders which, I believe, is the reason that loading docks prefer that configuration.

That said, I must confess to being a bit confused about why more forward tandems would necessarily protect a trailer structure. But then, I'm a tanker yanker.

 

If you looked at the trailer floor like a see saw, somewhere between the tandem and forward landing gear is a fulcrum. Now the trailer weights around 12000 to 15000 empty depending on type (Van or reefer) and so on. Put a forklift weight tons on one end its going to move.

In the old days tandems were wherever, Dock plates were supported by a form of suspension and were alive to the movements etc. Or just plain plates of steel. Motormen knew how to get into and out of trailers.

Once in a while someone slams into a trailer and if the tandems were at the 41 foot line etc (Really far forward) well its a big mess. Eventually the warehouses wanted and demanded the 53 foot trailer tandems back full. They did not give a whit in the 48 foot days before 53.

That I think is the difference the extra few feet of overhang unbalances the thing. Now you could have the tractor on it and it will hold it more or less and it's airride will take the bounce. But the warehouses when they get a inch they became dictators and take a mile. Make a mess of docking just to save a trailer sometime.

If you were not lazy docking with tandems back is no problem. Dock as normal, then slide back prior to going into the door itself. Unhook, wind gear down take away lines etc and put the bobtail away and worse of all sit in a hard chair for up to 10 hours in a designated room with 50 others.

You learn fast how to work around having that in your trucking life by eliminating places like that and sometimes companies by moving to those with drop hook etc.

 

I think it is also the advent of air ride suspensions. Spring don't give that much, so the trailer didn't drop that much.

I was loading at a place with a 53' container and I couldn't slide the tandems (surprise surprise!) They told me it didnt matter because they didn't drop as much as the dryvans.

 

It will definitely take stress off your airbags if you slide them to the rear. I slide them back every time I have a heavy load regardless of what the shipper / receiver wants.

 

This is the reason we had drivers slide the tandems back. All about dock height and not killing the fork trucks.

 

That goes both ways. If fork trucks are dropping onto the bed of trailers, it's not good for either.

A lot of older docks were designed for trailers with larger diameter wheels as well. I've been to quite a few older docks that have poured thin slabs or build wooden platforms in order to raise the level that trailers sit at by a few inches.