You have this correct here. 1,000# per foot with no more than 6,000# in the first 8 feet is the formula I use to load pups. 20,000 is all we can scale on the drives of a single axle and I've had trailers as light as 17,000# over-weight on my drives. I have loaded thousands of pups at Con-way Freight so here are a few other tips for loading the 28 footers.
1. Placing heavy freight on the back does not offset a nose heavy pup on a scale. The trailer axle is all the way at the back so all you are doing is adding to that axle. If the above formula is not followed and the trailer is nose heavy, no amount of weight on the tail will scale the drives.
2. Please, please, please, don't load 12,000# of freight on the last 10' of an 18,000# trailer. It will scale but I have to pull it. I did this to myself Saturday morning. I was in a hurry - any LTL line driver can relate - I would not do that if I was not the one pulling it - loaded 12,000# on the back of what ended up being my back box and fought that set the entire way home. Imagine putting a dumbbell at the end of a whip - that is the effect this creates.
3. Hazmat totes. Please nail them to the floor using 2X4's. I would prefer 25,000# worth of totes did not slide to one side of my trailer. A typical tote load is 8 totes at 3,000# per tote. The proper way to load this is mt skids in the nose keeping the first 4' mt then 1, 2, 1, 2, 2. Nail the singles in with 2X4's and that load will scale every time and won't budge an inch.