is made up of a cylinder, a ram piston, a fuel pump, a built-in fuel tank, a lubricant oil tank, and an inertia oil pump that lubricates mechanically during operation.

The diesel pile hammer is about twice as fast as a conventional pneumatic, or steam, hammer of like size and weight. A conventional pneumatic hammer requires a 600-cubic-foot-per minute compressor to operate, while the diesel is a self-contained unit constructed in sizes that deliver up to 43,000 foot-pounds of energy per blow.

Pile-Driving Caps

A pile-driving CAP is a block (usually a steel block) that rests on the butt or head of the pile and protects it against damage by receiving and transmitting the blows of the hammer or ram. In the steam, or pneumatic, hammer, the cap is a part of the hammer. The cap with a drop or diesel hammer is a separate casting, with the lower part recessed to fit the head or butt of the pile, and the upper part recessed to contain a hardwood block which receives the blows of the hammer. The cap is fitted with a wire-rope sling so that the cap, as well as the hammer, may be raised to the top of the leads when positioning a pile in the leads. Pile CAPS are available for driving timber, concrete, sheet, and H-beam piles. Figure 8-20 shows an example of a steel H-pile and a special cap for driving.

Figure 8-20. - H-beam pile-driving cap.

Crane Safety

As the project supervisor of a pile-driving operation, you must be aware of the safety precautions and procedures involved when working with and around cranes.

Statistics on accidents show that a free moving power crane is one of the most destructive machines used in the Navy, as well as in private industry. Over one third of the victims of crane accidents are operators; more than one fourth are crew members other than operators. Ironically, the people who sustain the most injuries from cranes are the very ones who can do the most to prevent injuries. Most crane accidents are preventable simply because they are caused by situations, conditions, or actions under the control of the operating crew. The term preventable accident is illogical; if an accident were preventable, it would not be an accident, but an act of omission or commission by somebody.

Most crane work is, or should be, a coordinated activity of a team of skilled technicians and workers. The lives and well-being of the whole team are in the hands of each member of the team during a continually shifting scene requiring constant judgment and responsibility. The pile-driving crew is usually made up of the following personnel:

Rig operator

Signalman

Loftman

Hoisting engineer

Hook-on person

During any pile-driving operation, the SIGNALMAN is the boss of the rig and is normally the only person giving signals to the operator. The only signal any other person may give that the operator will obey is the EMERGENCY STOP SIGNAL. Refer to the Equipment Operator Basic, NAVEDTRA 12535, for more information regarding crane safety.

Pile-Driving Safety

Standard safety and accident prevention procedures developed to govern general construction operations apply also to pile-driving operations. Pile driving is hazardous, and personnel should take adequate care to be protected from injury. Close cooperation between the Equipment Operators and crew members (Builders/Steelworkers) is essential to avoid accidents.