Were these trailers braked? I’ve been told the driver didn’t have to get out of the cab to couple or uncouple, so what replaced the suzis, if they had brakes?
Star down under.:
Were these trailers braked? I’ve been told the driver didn’t have to get out of the cab to couple or uncouple, so what replaced the suzis, if they had brakes?
Yes, they were braked. But it was a mechanical system, not air. As I recall the coupling fitting on the tractor had a lever that was operated off the braking system. The trailer part of the coupling had a corresponding lever that aligned up with the tractor lever when coupled. Thus movement was transmitted to the trailer. This movement operated the brakes on the trailer. A similar arrangement of alignment of electrical contacts was used for lighting.
I used Scammel couplings years ago. In my experience they worked well. But as the trailer landing gear was quite narrow I often wondered if the trailer ever risked toppling over when uncoupled. I imagined that uneven land and an uneven lopsided load on the trailer might just cause it to topple. It never did for me and I never heard of it happening. But that narrow track always made me think!
Thanks Dipster, I have never seen one in the flesh.
Star down under.:
Thanks Disputer, I have never seen one in the flesh.
Heres a couple of photos Star Down Under they were vacuum assisted brakes on the prime mover to the mechanical linkage as Dipster explained a lot of moving wearing parts.
Dig
Drove an Albion, Thames Trader, and D type Ford all with Scammel coupling, but for the life of me cant remember how the braking worked, I know there where no air lines, it must have been similar to caravan over ride brakes, but there was a handbrake, the electric coupling was just contacts on the unit and the same on the trailer and when coupled they just touched, one thing I do remember is you had to keep your foot hard on the brake when pulled the uncoupling leaver if you didn’t it would fire you out like a bullet and drop on it’s knee’s, and you couldn’t wind it back up, you had to use jack’s, but after all that still they did their job…
Ossie
Thanks fellas, very informative. On the larger trucks that used this coupling, were air or vacuum over hydraulic brakes utilized?
In the early days of haulage a lot of lorry brakes were operated by pre stressed rods, front brakes were an optional extra [emoji848]
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Like ossie said about the electrical contacts, they were similar to a dodgem car with a springy contact rubbing on the other.
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An ingenious system that unfortunately could not keep up with new C & U regs.
mechanical-horse-club.org.uk … upling.htm
If you enlarge the photo of the scarab you can quite clearly see the braking rod on the offside
When you pressed the footbrake this pushed the rod against a corresponding rod on the trailer
activating the trailer brakes.
Wheel Nut:
In the early days of haulage a lot of lorry brakes were operated by pre stressed rods, front brakes were an optional extra [emoji848]Sent from my iPhone using Tapatalk
I had a Seddon Carrimore around 1951 time and braking was a vacuum / rods system on trailer .vacuum line to turn table which auto lined up which fed vac tank on trailer, rod out of tank to cross rods to brakes , whether it was a feature or BRS mod but braking was to trailer slightly in advance of tractor which served to straighten the outfit up ,I never once had a jacknife despite the winters we had those days . toshboy
One of my very early driving jobs was driving a Bedford TK with a Scammel coupling.
That particular vehicle used a plug and socket type lighting connection,as today’s systems,all the trailers had obviously been rewired to this type of lighting system,I presume the original system was subject to weather conditions and was therefore unreliable in operation.
David
There were some Scammell coupling type dollies on one of my customer’s farms up until recently. These had an air brake chamber mounted on the centre line of the coupling to push against a lever on the trailer which then operated the mechanical brakes on the trailer. They still have a couple of trailers used as storage so I will have a look at the trailer end. The Bedford w/shop manual shows the tractor system, the trailer brakes are operated by no 14. The diagram is for a late production vehicle, by which time ( 1973) it was assumed that some trailers would be air braked so the mechanical actuator is really part of the secondary system. The hollow yellow dot is a female C coupling to which the tractor yellow line is coupled to operate the trailer actuator. The same way as would be done with the blue line if a standard three line tractor was coupled to a standard two line trailer.
Thanks for your help fellows, insightful and informative.
To cause chaos just Spin the coupling round ½ a turn with a scaffold tube.
Dave…
you could get a 5th wheel converter so that the scammell coupling tractor unit could couple up to king pin trailers