General Requirements >> Machinery and Piping Systems

Performing work on machinery and piping systems present in the shipyard may expose workers to injuries due to unanticipated machinery movement or release of materials (such as water, steam, oil). These systems may include:

Proper precautions, including blanking and securing machinery and piping, must be taken to prevent injuries. [29 CFR 1915.163(a)]

Note: Confined space entry is one of the leading hazards associated with barge cleaning. Review Ship Repair: Confined or Enclosed Spaces and Other Dangerous Atmospheres for information on how to protect workers from this hazard.

Figure 1: Boilermaker working on boiler piping system

Potential Hazards

Workers injured (for example, burned) from the exposure to:

  • High-temperature steam, water, or oil, which may enter the work area from an interconnecting system.
  • Explosion of hydrogen gas, which may be generated during acid cleaning processes. See Fire and Explosion Hazards under the Cleaning Operations page.
Figure 2: Acid from acid tank can cause flammable gases when used for cleaning boilers

Requirements and Example Solutions

  • Working in a dead boiler while the adjacent boiler is live requires the piping and valves between the boilers to be isolated by securing, blanking and tagging. [29 CFR 1915.162(a)(1)]
  • Tags must not be removed nor the valves unblanked until the work is completed. [29 CFR 1915.162(a)(1)]
  • Where valves are welded instead of bolted, at least two isolation and shutoff valves connecting the dead boiler with the live system or systems must be secured, locked, and tagged. [29 CFR 1915.162(a)(1)]
  • Drains must be opened and drainage visually verified. [29 CFR 1915.162(a)(2)]
  • A warning sign indicating workers are in boilers must be conspicuously posted in the engine room (for example, near all boiler controls). [29 CFR 1915.162(a)(3)]
Figure 3: Valves near dead boiler closed and tagged during work

Note: Control of Hazardous Energy Sources (Lockout/Tagout) standard [29 CFR 1910.147], does not apply to Ship Repair.

Figure 4: Steam, air, water lines and valves present hazards when worked on

Potential Hazards

Workers injured (for example, burned) from the exposure to:

  • High temperature steam, water, or oil, which may enter the work area from the piping system (such as high or low-pressure steam, heating coils, thermal coils).
  • Explosion of hydrogen gas, which may be generated during cleaning of boilers. See Fire and Explosion Hazards under Cleaning Operations.
Figure 5: Inert gas piping system isolated by blanking

Requirements and Example Solutions

  • Working on dead systems that are connected to live systems requires the piping and valves between the systems to be isolated by securing, blanking, and tagging. [29 CFR 1915.162(a)(1)]
  • Tags must not be removed nor the valves unblanked until the work is completed. [29 CFR 1915.162(a)(1)]
  • Where valves are welded instead of bolted, at least two isolation and shutoff valves connecting the dead system with the live system or systems must be secured, locked, and tagged. [29 CFR 1915.162(a)(1)]
  • Drains must be opened and drainage visually verified. [29 CFR 1915.162(a)(2)]
Figure 6: Blank in piping system verified in place by Certified Marine Chemist

Note: Control of Hazardous Energy Sources (Lockout/Tagout) standard [29 CFR 1910.147], does not apply to Shipyard Employment.

Figure 7: Workers removing main shaft gear

Potential Hazard

Workers may be injured by being struck by, caught in, or caught between machinery and other objects (such as tail and intermediate shafts, propellers, gears).

Figure 8: Thrust bearing and shaft guarded and clear of workers

Requirements and Example Solutions

Before turning over the engine or rotating the shaft and propeller:

  • Jacking gear (jacking engine) must be engaged to prevent the main engine from turning over, and signs must be posted at the throttle. [29 CFR 1915.164(a)(1)]
  • Stop valves on steam-driven jacking gear (jacking engine) must be secured, locked, and tagged. [29 CFR 1915.164(a)(2)]
  • The circuits controlling electrically driven jacking gear (jacking engine) must be de-energized by removing the fuse or opening the breaker or switch. The breaker, switch or fuse location must be tagged. [29 CFR 1915.164(a)(3)]
  • Checks must be made to ensure that all workers, equipment, and tools are clear of the engine, reduction gear, connecting accessories, and propeller. [29 CFR 1915.164(b) and (d)]
  • A warning sign indicating work is being conducted on or around the propeller must be conspicuously posted in the engine room. [29 CFR 1915.164(c)]

Note: Control of Hazardous Energy Sources (Lockout/Tagout) standard [29 CFR 1910.147], does not apply to Shipyard Employment.

Figure 9: Movement of anchor windlass and chain can present crushing hazards

Potential Hazard

Workers may be injured by being struck by, caught in, or caught between by the sudden movement of anchor chains or windlass.

Figure 10: Winch and cathead can present "caught in" hazard

Requirements and Example Solutions

Before working on the anchor windlass (for example, an anchor winch) or any of its attached accessories (e.g., cables, chains) ensure: [29 CFR 1915.165(a)]

  • Devil claws must be secured to the anchor chains to prevent the anchor from falling. [29 CFR 1915.165(a)(1)]
  • Riding pawls (such as dogs) must be engaged to prevent rotation of the windlass. [29 CFR 1915.165(a)(2)]
  • When devil claws and riding pawls are absent, anchor chains must be secured to the vessel. [29 CFR 1915.165(a)(3)]
Figure 11: Anchor chain secured by wire cables (instead of devil claws) to prevent the anchor from falling

Note: Control of Hazardous Energy Sources (Lockout/Tagout) standard [29 CFR 1910.147], does not apply to Shipyard Employment.