As used in this chapter, the following terms shall have the meanings
indicated:
SLED
Any sled, boat or other contrivance which is propelled by motor-driven
propellers, and which is used to convey persons on the surface of ice.
All sled propellers shall be enclosed by a guard of a suitable design
to prevent them from coming in contact with persons who may be in the way
of a sled.
Every propeller guard shall have a frame and support of sufficient strength
to resist the weight of a person struck by or thrown against the guard. No
propeller guard shall have an opening at its point or edge greater than two
inches square.
All motors shall have an automatic device in the ignition system, which
will permit the motor to operate only when the operator is at the control
of the sled so that the motor shall shut off automatically when the operator
leaves the control.