Join us






The Policy of the Somersetshire Coal Canal Society for the safe operation of

Allen Scythe, Serial Number 120945F

(herinafter referred to as "the machine").





No person shall be permitted to operate the machine, except for the purpose of training under close supervision, until the Work Party Manager is satisfied that they are a competent person. A competent person is one who in the opinion of the Work Party Manager:

1) Is of mature, sober and sound mind.

2) Has sufficient physical strength to operate the machine safely in the prevailing circumstances.

3) Has received training in the safe operation of the machine and has:

a) Read and understood the instructions in the manufacturer's handbook ("The Allen Self-Propelled Motor Scythe Model T.S." published by John Allen & Sons (Oxford) Ltd.)

b) Read and understood any supplementary safety instructions issued by the Somersetshire Coal Canal Society

c) Demonstrated competence to operate the machine safely to the satisfaction of the Work Party Manager or his approved deputy.

The Work Party Manager or his approved deputy may at any time withdraw permission to use the machine for any reason. He may restrict the type of work to be undertaken, restrict the work area and give specific directions for the operation of the machine so as to ensure safety in any special circumstances which may arise.



Normally the machine shall be operated by a crew of two operators:

1) The Machine Operator
The Machine operator is responsible for starting and stopping the machine and for steering it and controlling it so as to work in a safe and effective manner.

2) The Safety Operator
The Safety Operator is responsible for maintaining a lookout for potential hazards and for warning the Machine Operator. He should ensure that bystanders do not enter the work area and should assist the Machine Operator, if required, in case of difficulty.


No part of any operator is permitted to be forward of the machine's road wheel axle when the engine is running. (Forward means in the direction of the cutter bar.) Normally the Machine Operator will walk between or behind the handlebars and the Safety Operator will be free to move about (having regard for his own safety) so as to keep a lookout for obstacles and to be ready to assist in controlling the machine if necessary. If the Machine Operator is incapacitated, the Safety Operator shall stop the machine.


After working for some time (the duration of which will depend on the nature of the work), the two operators should exchange duties, so as to prevent danger arising from operator fatigue. Under conditions of exceptionally heavy work, a third operator will be necessary so that by rotating the duties, each operator in turn can be given a period of rest.


No adjustments, unclogging, lifting, recovery or other work shall be undertaken on the machine until the engine is stopped and the sparking plug connector has been removed from the plug.


No person other than a competent operator shall be permitted to remain in the area of work while the engine is running. If a bystander inadvertently enters the work area, the engine must be stopped immediately.


Downloadable .rtf version




Prepared by the Somersetshire Coal Canal Society

for safe operation of Allen Scythe, Serial Number 120945F

fitted with "Villiers Mk. 25" 4-stroke petrol engine

(herinafter referred to as "the machine")



This information is intended as a supplement to the manufacturer's handbook ("The Allen Self-Propelled Motor Scythe Model T.S." published by John Allen & Sons (Oxford) Ltd.) and should be read in conjunction with it. A summary of the manufacturer's instructions will be found on a plate attached to the engine cover, which serves as a reminder when the machine is on location.



This particular model is fitted with "Villiers Mk. 25" 4-stroke petrol engine, it was designed to be used with leaded fuel, not 2-stroke mixture. The use of neat unleaded fuel may result in damage to the exhaust valves, so if unleaded fuel is to be used, it must be augmented by a lead-substitute additive or an upper cylinder lubricant (such as 'Redex'), which is mixed with the fuel in the proportions recommended by the additive manufacturer.


Modern lubricants with similar viscosity ratings to those recommended in the handbook should be used for the engine, the gearbox and various lubrication points.




The risks identified below are in addition to the usual risks associated with petrol-driven vehicles and mowing machines.



The cutter blades operate whenever the engine is running.

No part of the operator's body shall be in front of the road wheel axle when the engine is running. During the starting and stopping operations, the physical layout of the machine ensures that the operator has to be located in a safe position. The operator should ensure that no other person is in front of the machine and the clutch is disengaged before starting it. The machine shall never be left unattended with the engine running.


The clutch, which controls rotation of the road wheels, does not disengage automatically when the clutch handle is released

A lever associated with the clutch handle has to be pulled to disengage the clutch. This lever performs two functions: it releases the clutch handle and it engages a servo mechanism which forces the clutch dogs to disengage regardless of the load upon them. The operator must be aware of the need to pull this lever firmly and hold it fully backwards until the forward motion of the machine ceases.


Once started, the engine will run until deprived of fuel. Shutting the throttle in the manner described in the handbook does not always stop a warm engine promptly.

The SCCS has fitted an electrical stopping device to the throttle lever. Pulling the lever backwards and downwards to its slowest speed position will immediately stop the engine. If this fails to operate or if the operator cannot reach it for any reason, the sparking plug cap should be pulled off to stop the engine in an emergency (taking care to avoid touching the rotating starter pulley). If the Machine Operator is incapacitated, the Safety Operator shall stop the machine.


This particular type of engine poses a high risk of 'kicking-back' during starting.

Only an approved toggle-ended cord similar to that shown in the handbook shall be used for starting the engine. It is important that the toggle can be pulled safely from the operator's grasp if the engine 'kicks-back'; under no circumstances should the starting cord be formed into a loop or tied around the operator's arm, wrist or hand in an attempt to gain extra purchase. If the starting cord is pulled in the manner described in the handbook, the risk of 'kick-back' is minimised.


The loose starter rope may become caught up in the machine or operator if it is left lying around.

Immediately the engine starts, stow the rope by winding it around the cleats on the right-hand handlebar and secure it in an approved manner.


The rotating starter pulley is exposed. It has a smooth periphery except for the angled rope notch and does not drive a belt, so there is little risk of anything becoming drawn into it. The main risk is of minor skin injuries due to friction or laceration.

It is not practical to guard the pulley as this would prevent it from being used to start the engine, so operators must be trained to work safely so as to avoid risk of contact with it. The operator should wear appropriate clothing with no loose parts; long hair should be tied back or worn under a cap. Under normal circumstances there is no need for anyone to be near the pulley, but when stopping the engine in an emergency by disconnecting the sparking plug lead, the operator must be aware of the risk the pulley poses.


The machine is heavy and liable to be deflected from its intended course by collision with objects such as tree stumps and large blocks of masonry which are sometimes found in the vicinity of abandoned canals.

On rough ground, to prevent injury from any sudden sideways movement of the machine, the operator shall avoid holding the handlebars with rigid arms or standing directly between them. The Safety Operator shall keep watch for obstructions and warn the Machine Operator of their presence. The Safety Operator shall be available to assist the Machine Operator in keeping control of the machine under difficult circumstances and shall stop the machine if the Machine Operator is incapacitated or thrown off balance by a sudden unexpected deflection of the machine.


The ratchet drive system to the road wheels allows the machine to freewheel downhill. This could result in the machine running away from the operator on steep downhill slopes.

Before descending a slope the Machine Operator shall engage the over-run pawls in the manner described in the handbook. This can usually be done safely with the engine running, provided the operator remains behind the road wheel axle.


On a steep slope, either uphill or downhill , a single operator may have insufficient strength to control the machine if the clutch is disengaged. This could result in the machine running away forwards or running backwards towards the operator.

The operator should be trained never to disengage the clutch on a steep hill. In the event of needing to stop, the throttle should be closed, thereby stopping the engine. The operator will then need to obtain assistance to manœver the machine to a safe place and restart the engine. If circumstances permit, the operator may turn the machine across the direction of slope, which will allow the clutch to be disengaged safely.



Always check that the clutch is disengaged before attempting to start the engine.

If the engine fails to start, check the following points:

1) Fuel in tank?

2) Fuel tap on?

3) Plug cap on?

4) Throttle lever set half open?


If the engine is extremely difficult to rotate with the starter cord, check that the cutter bar has not been dislodged from its correct alignment by a heavy collision. If it has, use the hammer and brass drift, which are included in the tool kit, to tap it back into place.

If the engine does not run at normal speed and fails to respond to the throttle properly, check to see if the bowden cable has been dislodged from the throttle control by a previous rapid movement of the throttle lever.

If the engine is sluggish and smoke appears in the exhaust gasses, check that the choke 'strangler' has not been left closed by mistake.

If the engine repeatedly speeds up, misfires and slows down, suspect that the throttle is set too high for the load on the engine.

If the machine is extremely difficult to steer, check that the over-run pawls have not been left engaged by mistake..

If the cutting action produces a shaking motion in the vegetation as it is cut, the cutter bar is operating correctly, but if the foliage is being pushed flat without a shaking action, the cutter bar may be choked with previously-cut material. This can sometimes be cleared by declutching and pulling the machine backwards whilst simultaneously shaking the handles up and down to throw the cut material off the cutter bar. If that action is ineffective, the engine must be stopped, the sparking plug cap removed and the cutter bar cleared by hand or with a suitable tool.

In cases of frequent repeated choking of the cutter bar, an experienced Safety Operator may use a stick, which must be at least 2 metres long, to carefully dislodge the material from the cutter bar without stopping the engine.. The Safety Operator must signal his intentions to the Machine Operator and await an acknowledgement before commencing. The clutch must be disengaged throughout the procedure and the Safety Operator must never stand in front of the machine.


The machine should not be driven through the middle of thick vegetation or high brambles as the operator will be obliged to follow and may become caught up in the bushes and unable to control the machine properly. The job should be tackled in a series of passes along the side of the vegetation, cutting in a little further at each pass. High vegetation on the left hand side of the machine may repeatedly catch in the throttle and shut off the engine unnecessarily; if this occurs, cut in one direction only, with the vegetation on the right hand side.  


Downloadable .rtf version 


For further information on Allen Motor Scythes:

Old Lawn Mower Club

Allen Scythe spares

Historic farming


Return to home page

Return to top of this page