Diagram
 key
Kit 5300

the Rover

Capstan Winch

The Land-Rover capstan winch has a 8 or 10 sided drum and was designed for laid rope, not multiplait (multiplait should be used on a smooth drum). Manilla (a sort of grass) is best for hauling since it will stretch before breaking unlike hemp. Generally synthetic ropes should not be used as the heat generated whilst it is slipping can melt the rope and damage it. The only disadvantage of capstan winches is that the engine must be running to use it.

Advantages:
- Light weight.
- Easy to use. 100% reliable, works under water or mud.
- No drain on electrical system.
- Precise control of the load and line speed - in or out.
- It's a working winch - you can use it all day long.

Disadvantages:
- Difficult to use if rope is wet or frozen.
- Only works if engine is running.
- Must be engaged with the engine stationary, though it can be disengaged while running.
- Line pull limited to 3,000lbs on some versions, though this can be almost doubled with a snatch block.

Sheer Pins:
There are two shear pins on the Fairey winch: One is part of the drive shaft to the winch from the starter dog, one is part of the capastan itself. The first one is the weakest one of the two.
They are not too difficult to replace, so long as you get the outer and inner parts of the shaft (which the pins connect to operate the winch) lined up, and so long as you can get at the underneath of the winch (i.e. just in front of the front chassis cross member). You can easily line up the holes using a steel version of the shear pin, which you can make up yourself. Such a pin will also allow you to hand crank the engine without risking breaking the shear pin. It should not be used for winching of course!
You should be able to winch 1.5 ton objects up steep 1:2 or 1:1 slopes, with a thick nylon rope. The farey capstan winch, if used with a steel shear pin has a load capcaity of 10 000 Pounds!

Use:
Take 3 turns upwards round the capstan and tail the rope from the side, far enough away in case anything lets go. When in use with proper rope, you will find that the the turning of the drum as you tail the winch will cause the turns of rope to ride up. The further up the drum the rope goes, the steeper the taper becomes, so the top turns of rope bind tighter onto the lower ones. This reduces the force you need to put in tailing. Most capstans on ships have a limit to the torque they can generate, either because of the motor power if electric or steam, or a pressure relief if hydraulic. The Land-Rover one has, as far as I can remember, a shear pin. Rather terminal!

Rope:
Note: If you use mm, then you are talking diameter, but if you talk inches then it is circumfence. So, a 3/4" rope will be rather small, about 6mm diameter actually. You should want something like a 20mm rope.

Rope Types:
HEMP / MANILA:- Since both these are made from natural materials, they tend to rot with age and their strength can be adversely affected with no visible signs of deterioration.

NYLON / Terilyne:- Good strength but too springy/elastic, the outer covering will melt due to friction on the drum.

Kevlar:- Excellent strength, no stretch, does have a synthetic outer so it will melt under heavy friction, when it snaps, it goes with a bang, suddenly.

Poly cotton/terilyne inner:- Like that used by Yachties for "sheets", High strength, low stretch, soft to handle, not cheap.

Notes:
Never use wire on an ordinary capstan, wire should be greased to preserve it and it would not drive properly, it will not bend tightly enough if of large enough diameter for the capstan, the turns can bind or lock preventing you from releasing it, and it will quickly wear out the ridges on the drum. The main reason is safety though, imagine a snapped cable with you standing in front holding the tail end!
After a short while, wire will form into coils as it wraps round the drum, thus becoming awkward to handle and sprigs of wire will break, shredding your hands in the process. Also the friction of a rope round the drum is greater (3 turns) than you can get with wire, and far more handleable.
BT cable pulling gangs use 16mm dia. poly covered kevlar stranded rope, SWL 3Tonnes, that should be enough for most people.

home