Q: Prototype 1 truck freight/work car?

So I brought the Walthers 75th Anniversary Catalog, and flipping through came to the Couplers section, which has a whimsical picture of a model jib car riding on one (1) standard (journal bearing) freight truck. Then, of course, I began to overanalyze this model, feeling if such a thing existed in the prototype world it would ride very unbalanced (lacking the famous 3 point suspension modelers are advised of, or the 4 point suspension that prototype cars have).
Any prototype 2 axle car I have seen of (such as scale-test cars, work cars, british freight wagons and yes, even intermodal 4 runners) had each axle attached separately and did not use a single truck - so is it even possible to have a prototype car riding on one truck only, and for it to be stable enough to be usable in a train (either revenue or MOW)? And has there been one in real life.

They existed. TTX had a set of like 100 cars in the mid 80's. They have all been scrapped. They were too light, and most railroads had severe restrictions on them, such as they could not be in a train when not loaded except after the last loaded car, they did not track right on tight track and they could only carry so much weight

I just tried finding a picture of one, but could not

crazy_nip wrote:They existed. TTX had a set of like 100 cars in the mid 80's. They have all been scrapped. They were too light, and most railroads had severe restrictions on them, such as they could not be in a train when not loaded except after the last loaded car, they did not track right on tight track and they could only carry so much weight

I just tried finding a picture of one, but could not

Nip, I think you misunderstood me.
First, sounds like you are discussing the TTOX Front Runner (4 Runner)s
Here's a image of a model: http://www.westerndepot.com/catalog/pro ... s_id=15766
Single axle yes, but as you can see not one single freight truck - there are, in effect, 2 trucks w/ 1 axle apiece. Kind of like this scale test car: http://imagescn.technomuses.ca/_images/ ... 004233.jpg although those axles may be more or less solidy attached to the frame.
No, what I mean is a car, riding on one (normal) single 2-axle freight truck like this 'Deer Creek' jib-crane car model.
Come to think of it, didn't Walther's old Oscar/Piker models ride on one 3-axle truck? http://home.att.net/~Berliner-Ultrasoni ... l#pikroscr - yep, so it's not a new model concept - but is it even feasible in the prototype world?

I have seen scale test cars, riding on a single truck, very common, actually. In days of old, Bobber Cabooses also rode on a single truck, on some smaller railroads. You are correct in thinking they are not stable, with only a single centercup, to support the weight, although they can receive cushioning snubbers, at opposite corners, of the truck frames. In reality, freight cars have only two points of contact/suspension, and that's again, in the centercups. it could have 100 wheels on the rail, but the car rides the bolster and cups, not the wheels, as far as suspending the weight of the car is concerned. The truckframes ride on the wheels, the bolster rides the trucks, and the car, or loco rides the cups, in the tops of the bolsters. Regards

Sir Ray wrote:So I brought the Walthers 75th Anniversary Catalog, and flipping through came to the Couplers section, which has a whimsical picture of a model jib car riding on one (1) standard (journal bearing) freight truck. Then, of course, I began to overanalyze this model, feeling if such a thing existed in the prototype world it would ride very unbalanced (lacking the famous 3 point suspension modelers are advised of, or the 4 point suspension that prototype cars have).
Any prototype 2 axle car I have seen of (such as scale-test cars, work cars, british freight wagons and yes, even intermodal 4 runners) had each axle attached separately and did not use a single truck - so is it even possible to have a prototype car riding on one truck only, and for it to be stable enough to be usable in a train (either revenue or MOW)? And has there been one in real life.

There is no need to place a "standard" truck under a car that is designed for only two axles. The purpose of a separate truck is to allow the wheelsets to swivel independently of the car frame to accomodate curves. It is necessary for the wheels at each end of the car to swivel in different directions. On a two axle car there is no reason for the car frame and truck frame to not be in alignment (and yes I know that the 4 runners allowed some axle swivel, but it was very limited.) Additionally, with a standard freight truck the three points of support it offers are all in a line perpendicular to the track. So a car with only one truck would have zero stability front to back.

I wasn't counting the side bearings, even though they are now supposed to be "constant contact". On an empty, they are rarely supporting the weight of the lateral motions, and the small car he mentioned wouldn't have the newer constant contact side bearings, we see today.