Ive always been curious about these trailers

My guess would be they got rid of them because you couldn’t hit a customer dock with them. Good for like line haul but the local guys couldn’t use them for anything……

 

They were high cube trailers and the belly was loaded first and then flaps were lowed over the belly so as those boxes didn’t get crushed. They also had rollers down the center of the trailer to the nose to make loading and unloading easier. Most customers that they were dropped at used a conveyer on their dock from a packing/labeling station. The boxes were then pushed up in to the trailer where they were hand stacked on the trailer. The landing gear was air over hydraulic and the trailer would raise the nose several feet up in the air to make offloading easier at some smaller hubs. Inside UPS hubs is mostly conveyors and is not like a normal freight dock with open spaces and forklifts. I don’t know why they got away from these trailers but there were still a few floating around in 2012 when I left. I haven’t seen one in years on the road. It seems that now with the exception of Amazon and other shippers like them, most load palletized packages shrink wrapped and UPS unloads them one box at a time from the pallets. The conveyor goes further up in the trailer as they unload and the pallets are not moved. Later in the pallet yard they are pulled to the back of the trailer and either sent back to large customers or sold to pallet recyclers. Occasionally the landing gear wouldn’t raise back up in cold weather, but generally tugging on it caused them to retract. Sometimes one would break causing a hydraulic mess. FedEx ground had traditional crank style landing gear on all of those I have noticed.

 

This picture is taken from the nose looking towards the rear. You see all the wood panels clipped to the wall. They were lowered after packages were loaded to that level.

 

There were many drop trailer customers that shipped a trailer or more every day that specified that kind of trailer to be dropped as they had rollers on their dock.

 

I was told back then they were switching over to flat bottom trailers in ~2003ish because we weren't cubing out the drop frames well enough. Maybe it was because I was just a loader that they were telling me that Now they have manual platform decks in most of their trailers.

 

Far as I can say, ups still runs some as double and triples across 80/90 turnpike.

 

@Banker pretty much covered it for the UPS units.
There was an article written by one of the many truck historians a while back that covered the history of these trailers. A long since fallen flag western carrier in the 1950’s came up with the idea and had a few built in the with folding reinforced floor panels so small packages could be loaded in the belly first and the floor would still be flat and strong and lift trucks could still be driven in.
There was also some western flatbed outfits that had some outside frame trailers made with the belly open under the floor for the same reason. Loose odds and ends could be carried in the belly while big bulk above it on the deck. Was also good for return freight like mail or small things of that nature back in the day when everyone ran a back haul of some kind even if it wasn’t normal for the type of trailer you pulled.

keep in mind back then 30 foot long 96” wide and 12”-8” tall was max size for a otr trailer so they were trying to use as much space as they could in those dimensions. A lot of trailers were barely 92” wide deck.

 

CFCC ran drop belly pups as well. There’s was set up that an air actuated panel in the floor rose up and slid forward for loading with hand freight. The panel then slid back into place over the lower compartment and it was loaded like a regular LTL pup with forklifts, dollies or whatever. The belly section was about 10’ long from behind the landing gear and about as deep as what you see on the Buster Brown drop belly trailers. This would have been in the late 80’s and early 90’s. I don’t know if any survived the merger with ABF