Engineering & Design Considerations for Shipboard Safety · Engineering & Design Considerations for Shipboard Safety Timothy Keyser, ... - Human Error: Dropping tools ... Machinery

US Army Corps of EngineersBUILDING STRONG®

Engineering & Design Considerations for Shipboard SafetyTimothy Keyser, P.E.

Presentation forPIANC USA / COPRI ASCEDredging 2012

San Diego, CA

October 23, 2012

BUILDING STRONG®DREDGING 2012

OUTLINE

• Marine Arc Flash Hazards• Subchapter M – Inspection of Towing Vessels• Environmental Design Considerations


Hazards Associated with Arcing Faults• Arc Blast

Large current arcing through airTemperature nears 35,000 degF

• Thermal RadiationImpact depends on clothing,

area exposed

• Pressure WaveForce from blast25kA @ 2 ft = 480 pounds

• Projectiles/DebrisMolten metal, debris


Causes of an Arc Flash Most common causes of Arc Flash:

- Switching Operations: Unavoidable, but switchboard design can help to mitigate the effect, e.g. the use of arc chutes;

- Equipment Failure & Degradation: This can include the breakdown of insulation via partial discharge, damage to equipment from external influences and creepage and clearance faults;

- Human Error: Dropping tools across live conductors, accidental contact with energized parts;

- Improper Work Procedure: Incorrect live working on exposed conductors or the removal of covers for maintenance of energized equipment;

- Environmental Conditions: Dirt (or even dust) build-up on exposed conductors, or organic compounds (e.g. oil) in the atmosphere surrounding the conductors.

The most common cause of an Arc Flash is human error, therefore: - The majority of Arc Flash events occur when equipment is being worked on; - Personnel are often in the vicinity, meaning a high chance of injury.


Arc Flash Standards• U.S. “Marine” Arc Flash Standards = None

- USCG is the U.S. Marine Regulatory Agency- Mitigation Required by Shoreside Standards May Conflict with

USCG Regulations

• Shoreside Standards- IEEE 1584 - Guide to Performing Arc Flash Calculations- NFPA 70 - National Electrical Code®- NFPA 70E - Standard for Electrical Safety in the Workplace

• This standard does not cover safety-related work practices for installations in ships, watercraft

- OSHA 1910 and OSHA 1926


Arc Flash Risk Mitigation

Prevention – The best way to deal with the risk of the arc flash hazard is to stop the arc flash event from occurring

Protection - Both personnel and ships systems need to be protected from injury and damage


Arc Flash Risk Mitigation• Prevention

– Remote Operations: Racking of breakers, Switching

– Switching Operations: Internal arc qualified switchgear (arc chutes)

– Operating procedures: De-energize equipment, second person a safe distance away, equipment maintenance, thermal surveys

– Tooling: Use insulated tools– Training: Ensure personnel have awareness

of Arc Flash


Arc Flash Risk MitigationProtection• Minimize Available Fault Current – Minimize the amount of

online generation. • Arcing Time – Light and current-based protection can be set up

with dedicated Arc Flash protection relays• Distance – Remote operation

– Increased distance = Lower level of incident energy • Personal Protective Equipment


Marine Arc Flash Summary• The Arc Flash hazard on Marine Vessels needs to be recognized and assessed,

and appropriate control measures should be put in place so that both personneland essential equipment may be adequately protected.

• Personnel need to be made aware of the Arc Flash hazard through training.

• Prevention is about engineering Arc Flash out of new designs and reducing itslikelihood in existing plant, noting many causes are still currently due to humanerror and equipment failure

• Protection in most cases is very much a last line of defense


Subchapter MInspection of Towing VesselsApplicability & Compliance

• Applicability• US Flagged towing vessels > 26’ engaged in pushing,

pulling or hauling alongside• Towing vessels < 26’ if they are towing barges with

dangerous or hazardous materials• Compliance Options

• Develop and comply with a Towing Safety Management System (TSMS), use 3rd party auditors and inspectors

• Submit to an Annual Coast Guard Inspection

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Fire Protection (Part 142)

• Requirements for minimum number of portable and semi-portable fire extinguishers (generally only 3)

• Requirement for fixed system to be CG approved• Built after 2003, required to have fixed

system in engine room

• Fire pump requirement (specifications, operation, control)• Required to have fire detection system in

engine room, smoke alarms in berthing and heat detectors in galley.

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Machinery & Electrical System and Equipment (Part 143)

• Machinery and General Alarm requirements• Communications between engine room and pilothouse• Fuel system and Remote Shut-Off• Bilge Pumps• Redundant Systems• Pressure Vessels – relief valves at 110% of working pressure

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Machinery & Electrical System and Equipment (Part 143)

• Electrical Systems• Require a load analysis to be approved and appropriate power source

selected• Equipment, panel and cable marking requirements• Deadfront switchboard• Grounded electrical systems• Installation and wire way requirements

• Emergency lighting for 3 hrs• Pilothouse Alerter System

• Two sources of electricity for alarms, E-lights, navigation lights, pilothouse lights, radios and navigation equip (if battery: 3 hrs duration)

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Construction and Arrangement(Part 144)

• Structural Standards - ABS rules for intended route• Stability – must meet 46CFR170.173 (Unusual Proportion)• Emergency Escapes – 2 from quarters or spaces were crew are

normally employed• Rails or equivalent protection around the periphery of all decks• Exhaust – clear of woodwork and insulated

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Environmental Design Considerations

• EPA Vessel General Permit Consideration• Fill/Vent Containments• OWS• Non-Oil Bearings / EAL

• National Ballast Water Discharge Considerations• Fuel & Oil Off of the Shell• Noise & Vibration Considerations (ABS Crew Habitability

Guide Lines)• Human Engineering Design (ASTM F1166)

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DISCUSSIONS/QUESTIONS

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Timothy [email protected]: (215) 656-6171 C: (267) 275-2638

mailto:[email protected]

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Engineering & Design Considerations for Shipboard Safety · Engineering & Design Considerations for Shipboard Safety Timothy Keyser, ... - Human Error: Dropping tools ... Machinery