There appear to be several makes of portable internal combustion engine
power saws in use in the German Army.* The use of a power saw results in
from 4 to 8 times the output from hand-cutting. One hundred trees 8 to 12 inches in
diameter can be cut by a power saw in forty-five minutes.
A description, from a British source, of a light and heavy German power
saw follows. The heavy type cuts approximately ten percent faster than the light
* * *
|Weight (including fuel)||
|Capacity of fuel tank||
||3 1/2 pints||
||3 1/2 pints||
|Effective length cutting edge||
||3 ft 3 in||
||3 ft 3 in||
|Speed of cutting chain||
||1 3/4 to 2 1/2 pts/hr||
||2 1/2 to 3 pts/hr||
b. Light Power Saw
The German designation for the light power saw is leichte Kraftsäge.
The principal parts are the gasoline engine, the clutch, saw blade and saw
chain. The engine is a single cylinder two stroke engine and burns a mixture of
gasoline and oil.
Throttle control is by a Bowden cable actuated by a lever in front of the
left hand-carrying grip. This grip also swivels to operate the clutch, engaging the
clutch when turned outwards and disengaging when turned inwards. The grip is
locked in either of these positions by one of two apertures in a spring leaf
engaging a stud. A disengaging lever is provided under the grip. Two projections on
the grip engage the throttle lever and close the throttle automatically on
disengaging the clutch.
There is a reduction gear of 2.2 : 1 between the motor and the clutch.
The saw blade can be turned through 90° for horizontal or vertical cutting
and is locked in position by a lever.
The blade acts as guide for the cutting chain, the links of which carry
alternate right or left offset teeth which may also be alternated with non-offset
teeth. The far end of the blade carries a tensioning screw and an oil reservoir
for lubricating the chain.
A button for switching off the ignition is on the right-hand (fixed) carrying handle.
c. Heavy Power Saw
The German designation for the heavy power saw is schwere Kraftsäge. It
is generally similar to the light power saw, but being too heavy for hand use,
is provided with three adjustable legs, and a large bogie for wheeling into
position. The saw blade can be swivelled about the axis of the chain drive wheel, as
well as turned horizontal or vertical.
Lubricating oil is mixed with the fuel. If the machine is new, a mixture of
10 parts of gasoline with 1 part of motor oil is used for the first 50 hours, then
a 12 : 1 mixture, and finally, after 200 hours
running, a 15 : 1 mixture.
(2) Saw Sharpening
A sharpening device for the saw-chain, consisting of a small grinding
wheel, driven by a flexible coupling to the fly wheel of the saw motor, and a
positioning roller for the chain, is provided. The positioning roller is provided with
three grooves, which have studs to engage between the links of the chain, and are
cut at such angles as to present the front surfaces of the teeth to the grinding
surface. The motor is run at about 1,500 rpm with the throttle about 1/4 open.
The teeth usually require sharpening after cutting about 250 trees 10 to 14 inches
Before starting, set the saw blade in the required horizontal or vertical
position by releasing the securing lever, turning the blade until it clicks, and
re-engaging the lever.
1. Close cylinder head priming cock
2. Disengage clutch
3. Open fuel tap
4. Flood carburetor
5. Open throttle one quarter
6. Remove cover from starting disk
7. Wind the leather starting strap around the starting disk
8. Pull the leather starting strap smartly, holding the machine with the left hand and foot
1. Close the throttle
2. Open the cylinder head priming cock
3. After the machine has stopped, close the fuel tap.
* This equipment is generally found in German engineer units.