15 August 2002
Alternative Arrangement. If this arrangement is not possible, install
flushing/cooling pumps with minimum discharge pressures of 1024.21 kPa (150 psi,) at
most remote outlet. Arrange graving dock fire pumps in parallel operation for flushing
and cooling, and arrange series operation for standby fire protection.
Fire Pumps. Station fire protection system pumps should have at least
50 percent of the maximum fire flow requirements in diesel driven fire pumps. Dual
power driven fire pumps are not allowed by code (unless installed before the adoption of
the 1974 edition of NFPA 20). Fire pump installations shall conform to the provisions of
National Fire Protection Association (NFPA) Standard No. 20, Standard for the
Installation of Stationary Fire Pumps for Fire Protection.
Type of Piping. All piping for graving dock fire protection systems shall
be cement lined AWWA ductile iron pipe, class to suit required fire pressures, with
lugged and rodded joints and fittings (except the pipes in pumpwells and service
galleries should be flanged). Any joint of equal strength may be used, subject to the
approval of NAVFAC HQ.
Pipe Sizes. Where station systems are connected to drydock systems,
pipe sizes from station pumphouse to docks should be generous enough to provide
pressures for drydock flushing and cooling requirements.
Specific Requirements for Salt or Nonpotable Water. Provide salt or
nonpotable water to meet cooling/flushing and fire protection demands as contained in
MIL-HDBK 1025/2 Dockside Utilities. According to MIL-STD-1625C(SH) Notice 1,
Safety Certification Program for Drydocking Facilities and Shipbuilding Ways for U.S.
Navy Ships, (or latest edition), the minimum fire protection requirement for all
drydocking facilities is 1135.5 L/min (300 gpm) per 30.48 m (100 ft) of docked ship, at
1034.21 kPa (150 psi) at the most remote outlet.
Wastewater Collection. Segregation of sanitary sewage, industrial
wastewater and hydrostatic leakage water is required. Drydock and ship sewage will be
collected and discharged into the station sewerage system. Hydrostatic leakage not
mixed with industrial waste is not polluted, therefore can be pumped into receiving
waters, except at locations where local environmental regulations forbid it. Refer to
Sanitary Sewer System. All sewage and hotel wastes from ships in
drydock shall be collected and transported to a treatment plant. Preferably, locate a
sewer main on each side of the dock. Discharge of all sewage to a main on only one
side of the graving dock should be considered if local circumstances dictate. Provide
receiving manifolds located along the coping of the graving dock and connect to the
main sewer through laterals. Transport sewage from the ship to the manifold receiving
connection by way of a hose. Design the sewer system to meet peak flow rates from
the largest ship class for which the drydock is designed. These are contained in MIL-
HDBK 1025/2 Dockside Utilities. For additional design criteria refer to UFC 3-240-02,
Design - Wastewater Treatment System Augmenting Handbook.