Page 276 - Safety Memo

safety switches to prevent uncontrolled motion of the Pressurized Worksites
equipment before an employee may access the leads. 1600(f)
F. Fall protection must be provided when workers are exposed Pressurized worksites (also known as compressed-air worksites)
to unguarded platforms or walkways exceeding 7 1/2 ft. in are sites where employees perform duties in a pressurized
height. 1670(a) environment, such as a caisson. Employees working on
pressurized worksites may be exposed to some specific health
G. Walkways that are at least 20 inches wide must be and safety hazards due to compression and decompression.
provided for access to all work areas. 1600(h)
These hazards are similar to hazards found in diving operations,
H. Employees shall not ride the hammer, crane load block, or pressurized tunneling operations, and confined spaces.
overhaul ball. Sheet piling shall be firmly stabilized before Employees may develop decompression sickness (bends) from
workers are permitted to work on them. 1600(g) exposure to decompression. The symptoms of decompression
I. Where a drop hammer is used for driving piling, other than sickness include headache, unusual tiredness, rash, pain in one
sheet piling, a driving head or bonnet shall be provided to bell or more joints, tingling in the arms or legs, muscular weakness
the head of the pile and hold it true in the leads. 1600(h)(3) or paralysis, breathing difficulties, shock, unconsciousness, or
death.
The pile hammer, clamp, power unit, and supply hoses
shall be inspected in accordance with their manufacturer’s Also, in a pressurized work environment, structural failures or
recommendations. 1600(i) blowouts may occur. This may lead to the work area becoming
J. Adequate and accessible flotation gear (e.g., ring buoys, a inundated with mud and water, causing drowning and asphyxia.
lifesaving boat) must be provided to protect workers who A. Cal/OSHA must receive written notification at least seven days
are exposed to a drowning hazard. 1600(j), (k) before the work is started. 6075
K. The engine or winch operator shall receive signals only from a B. Regulatory requirements for pressurized (hyperbaric) work
designated signaler. 1600(l) environments include:
Exception: When an employee is aloft in the leads, the 1. Following the guidelines for proper compression of
hammer shall not be moved except on the signal of the employees as per 6080(a).
employee aloft.
2. Not subjecting employees to pressure exceeding 50
L. A hammer stop block is required. 1600(o) pounds per square inch. 6080(b)
M. Two steam (or compressed air) shutoff valves are required; 3. Not allowing employees working in compressed air to pass
one must be a quick-acting valve within reach of the hammer from the working chamber to atmospheric pressure until
operator. 1600(c)(2) after decompression, in accordance with 6085, 6090.
N. Rigs must be stabilized with guys or outriggers when needed. Exception: The requirements above do not apply in an
Hammers shall be lowered to the bottom of the leads while emergency. 6080
the pile driver is being moved (traveling). 1600(p)
4. Controlling decompression of employees as discussed
O. Piles shall be unloaded and stored in a controlled manner. in 6085.
1601
5. Decompression of employees in accordance with the
P. The rated capacity of the hammer’s suspension shall not specified decompression tables of the U.S. Navy Diving
be exceeded. The manufacturer’s recommendations for Manual, Volume 2, Chapter 9, 2008. 6085
extracting piling shall be observed at all times. 1600.1
Exception: Requirements #4 and #5 do not apply in an
Q. Barges or floats used in pile driving shall meet the emergency provided that employees are decompressed in
requirements of Article 13. accordance with decompression tables and procedures
recommended by the supervising physician.

110 Cal/OSHA Pocket Guide for the Construction Industry | June 2019 Cal/OSHA Pocket Guide for the Construction Industry | June 2019 111