NINJA II: The Fuel Cap He Opened to Check a Stalled Engine Nearly Killed Him

Utah Beach, 12 June 2013 — 04:00

NINJA II, a 7.99m aluminium potting and netting boat working out of Utah Beach in Normandy, had been fishing for whelks since 02:30. Two aboard: the skipper, 36, and a 20-year-old deckhand. Both properly qualified, both medically fit, neither reporting fatigue. Nothing about the morning suggested anything was wrong — until the auxiliary petrol-hydraulic motor that drove the pot-hauler winch simply stopped.

What Happened

The motor had been replaced at the start of the month and had needed a few dealer call-outs since — but had run perfectly for the five days before the accident. When it stalled just before the fourth string of pots, the skipper's first assumption was the obvious one: low on fuel. The motor sat in the wheelhouse, on the port side. He opened the fuel tank cap to check the level.

A violent explosion followed. The motor caught fire. The skipper suffered severe burns to his arms and face. With the wheelhouse now inaccessible, neither raising the alarm nor reaching the fire extinguisher was possible from inside it — the crew fought the fire with buckets of seawater instead, and got it under control. The electrical panel and every navigation and communication instrument were damaged by the heat. They beached the boat, hauled it out on its usual tractor and trailer, and drove the skipper to hospital themselves — 40km to Coutances. The owner only learned what had happened from a note left on board.

What the Investigation Found

BEAmer's investigation couldn't establish with certainty exactly what ignited the vapour, but the physical picture was clear enough. The most likely explanation: the engine had stalled from flooding, caused by a sticking needle valve letting too much fuel through to the carburettor (the tank feeds it under gravity pressure). A year on, investigators were still examining whether a badly-routed breather hose during the engine's installation had caused crankcase overpressure — and found the oil level in the crankcase unusually high, mixed with a significant quantity of petrol. What's certain is where it happened: petrol vapour (flash point 40°C) ignited in a confined space the moment the tank cap came off.