Mark 1 Sankey Trailer Breakaway Cable

[07BE16]

Can anybody help me with suggestions of the modifications required  to make a 'breakaway' cable work on a Mark 1 Sankey hitch?

I assume removing the brake shoes and limiting the load does not make it an unbraked trailer? (Then I would just need a secondary coupling to retain the trailer to the towing vehicle)

Thanks

Richard

[B series]

Unless the regulations (Construction and Use) have changed recently, you have an option to fit a breakaway cable to the trailer parking brake, OR fit a robust safety chain (I think two is good) that should attach to the chassis of the trailer, and two fixed points on the towing vehicle.

Personally if using a NATO hitch (always with the safety pin in place), and two safety chains crossed under the hitch, is the best way and has some built in system redundancy.

Reducing the loaded or unloaded weight of the trailer does not change alter the technical requirements. There is no reason to remove brake shoes or any other part of the braking system, which should be fully operational.

The above is my opinion, and you should confirm current technical requirements by reading the UK Construction and Use regulation which can be found on line somewhere.

 

[07BE16]

B-Series Thanks. I think if the trailer is braked you have to fit a cable that applies and causes the trailer brakes to remain on. The design of the braking system on a Mark 1 trailer appears to make it difficult to keep the brakes on, I just wondered how others had approached this.

[ruxy]

You state  Mk.1   Sankey  ,  I take it you mean a Mk.1 Sankey  WIDETRACK   ,  that has leaf springs.

[07BE16]

1952 1/2 ton Mark 1 

[B series]

 

Hi 07BE16

In my opinion the way you have you have attached the 50mm coupling to the NATO towing eye is not a good engineering practice. Hard to tell from the photos, but the metal sheet with the four bolts going through would need to be maybe 1/2 inch plate to take the bending forces generated by a loaded trailer. I cannot see via the photo how the 50mm coupling is attached to the square of sheet metal, but it does not give a good impression. Also what would stop the coupling rotating on the NATO tow eye, the clamping force of the four bolts will not stop rotation. Basically your modified hitch conversion / design is not a safe solution in my opinion.

 

Regards

B series

 

[07BE16]

The attachment of the 50mm ball is just temporary to move the unladen trailer a short distance to where it will be stored. The hitch is also bolted through a spacer filling in the towing ring and the position of the 2 bolts nearest the trailer stops rotation.

 I intend to tow the trailer behind my Champ with the standard military tow jaw and in future behind my Lightweight with a NATO hitch, I am just try to work out a means of applying the brakes via a breakaway cable

 

[ruxy]

That trailer with the impressed X stiffeners was introduced  1962.  Earlier would be a Brockhouse ,  shared ancestry of Sankey  & Rubery Owen components.

You tip the drawbar 180 degrees to alter hitch height.

Champ tow-hook IMHO not as safe as a D-B pintle (that is used correctly).

Commendable fitting a brake-away chain ,  operation would be same to any 1960'1970's  caravan.

However - these "upgrades" were not normally retrospective,  a D-B pintle fitted to your Champ would be best & IIRC bolt-hole centres are identical, may be safer than a inadvertent pull on a safety chain. 

A Defender/Wolf era drop-plate with the two loops for safety chains may be better, although I think the loops are a bit femmer.