Does anyone have access to Canadian Libraries for old Truck Magazines

Just a few thoughts and probably completely off base.

I don't think there is any official designation to what you are trying to find out.
Hook two trailers together and look we created a train. not an ''A'' train but it stuck. then came the ''B'' train which just differentiated from A train. then later came the ''c'' train which was a different hook up

Road trains would be the correct term I believe and were in Australia first.

 

Maybe try reaching out to the ATHS. The term A train isn’t used much in the states. It’s simply doubles or triples. Turnpike doubles or Rocky Mountain doubles. But either way the ATHS will be your best bet for the info you seek.

 

If you find the answer please share.

 

Might find a few pictures of the era if you check out oldtruckpictures on instagram it contains a lot of stuff from hank suderman collection

 

I grew up with my dad working as a mechanic for what was a medium sized bulk transport company that began buying others to expand their market. This was in the mid 60s. Maccam Transport (laterTrimac) did not pioneer "doubles" or A-trains but were very early adopters.
Doubles were equal length trailers connected by a single axle converter that has a 5th wheel plate on top and the trailers were also single axle and normally 24 to 28 ft long so that with a short cab-over tractor they could maximize capacity within the restrictive length laws. This was 60 ft and up to 65 ft in most jurisdictions at that time.
Doubles originally had to stay in the same max weight rules as a 5 axle semi trailer.
When we were allowed more weight for extra axles in the late 60s then short tandem trailers with single axle converters were allowed all though a restricted max weight (in Western Canada 110,000lbs).
Bulk A-trains came from that rise in gross weight increase. The 110,000 weight was on major(primary) roads only and smaller roads and lighter built(secondary) roads were a lot more restricted.
In western Canada at that time secondary roads were restricted to 74,000 lbs.
Bulk carriers started building shorter tandem axle trailers with larger capacity and a pintle hitch on the back,then an even shorter single axle trailers with a turntable axle/hitch on the front. When pulled by a short cab over tractor they could still stay under the length laws and carry up to 40% more load. The other advantage was that some areas could take a partial load on the primary road then a "full" secondary load further on.
B trains were found to be even better for some things due to better stability and ease of backing but were not as versatile for split loads.
As the weight and length laws changed in the 70s then super B trailers became feasible.
C-trains were used some and were found to be almost as stable as b-trains but again had maneuvering restrictions for the average driver. They are still used somewhat in the ltl industry but seldom in bulk carriers.

 

I was just flipping through an old book. This is not technically an A-train but it looks like at least one outfit ran a body job with a pup back in the early 1940s. Sounds like there were issues with length and not being able to legally run the canyon with it because of that reason.

 

Early road trains consisted of traction engines pulling multiple wagons. The first identified road trains operated into South Australia's Flinders Ranges from the Port Augusta area in the mid-19th century.[2] They displaced bullock teams for the carriage of minerals to port and were, in turn, superseded by railways.

 

While that may be true in the west, that's not how it went in ON. As I recall A trains were first then came B trains then came 5 axles and all were good for 140,000 lbs.
Backing up a or b trains was very similar, I have no experience with C trains but they came later and afaik were designed so you could dock the lead trailer without dropping the dolly or driving over the plate between the trailers, ie drop the headboard on the pup.
Also the c trains didn't have to find a place to leave the dolly on a split load and had some advantage on weight laws in places when split.

And for the old guys imagine a b-model mack, 187 hp, triplex and an A train at 140,000 lbs, Armstrong steering bias ply tires backing into the steelmill doors and load 90,000 lbs and head on down the road.

Oh yea ''no log books then, in On''. and they didn't push axle weights either.

 

Just to clarify, here is a picture of what he is asking about - it is where the rear trailer sits on the back of a special built front trailer. In Australia we were led to believe this was a Canadian idea

Original Aussie B-Double (Canadian B-Train):



What they are proposing - 27 metres long