Herb,
I think you are right. I have moved Eureka over 30 times in the last 15 years and have had quite a learning curve in the process. I have always used a ramp to avoid twisting of the frame and other damage, but through the years we have developed and refined a process that works well for Eureka. First, we use a lowboy with a removable goose neck that is big enough to "swallow" the locomotive. That is, big enough in the center well of the trailer so that the locomotive can sit level. This keeps the height of the load down, and makes for a stable ride.
Second, we try to use relatively small rail or square tubing that is strong enough to support the engine and clear the flanges, but small and light enough so that it can be put on and taken off the lowboy with minimum hassel. I use 1/4 inch thick square steel tubing that has steel flat stock "ties" welded between the two to hold the gauge.
Third, a ramp is needed to load the locomotive from the track upon which it is resting and transition it up to the track on the trailer. Here at my home we use a ramp made of two very large "I" beams, with the square tubing welded on the top. This is very handy for making the transition from the track in my yard to the trailer. We needed this type of ramp here because the transition from the home rail to the trailer is at a very odd angle and I have to deal with a crowned pavement. This "I" beam ramp is 45 feet long and as stout as hell. A large forklift is a handy tool to put it in place, unless there is an unlimited supply of workers to lug it around. This ramp has eliminated a huge job of building rail over cribbing over a 45 foot distance, which always gave me the willys to boot.
Fourth, When unloading at the sight being visited, we use a couple "T" rails for the ramp with gauge rods between them and cribbing for support. Of course, a set of points are needed to make the transition from the ramp rail to the rail in the ground.
As you know, there are a bunch of important details that must always be considered, such as towing the engine on and off the trailer, joints, cribbing, proper tie downs and clearances and safety items, like stopping etc.
However, our latest and greatest feat is the "grasshopper". On my 40 foot step deck, upon which we carry the tender, we have built a folding ramp on the back of the trailer. When the ramp is is the travel mode, it is folded up, and it looks like gigantic legs of a grasshopper...hence the name. With the flick of a switch, the ramp hydrolicly unfolds in place and locks when down. When the tender is lowered off to the visiting railroad, and when clear, we flick the switch and up the ramp folds back up. It is slick as....well you know. We are working on a system for the locomotive on the low boy.
My trucker and I have found that we are lazy and that this hydrolic stuff is really great for the avoidance of back breaking grunt work.
I know there is a lot of experience out there for loading and unloading locomtives and tenders,and everyone has their own ideas on the subject. But
I just thought our system might be of interest and give an idea to anyone wanting to move their NG locomotive that may be about the size of Eureka sometime in the future for that event I have been dreaming about.
Dan