A brain teaser

This reminds me of the sort of task we were given to solve at officer school.

You are anchored off a coral reef with no village or habitation nearby. The reef has coral, coconuts and crabs. Your diesel tank has dirt in it that is blocking the flow and leading to the engine stalling. The tank is full to the top. You have three 10 liter cans of fuel but they are also full. There is a drain plug but if you open it, all the fuel will run out and you will never get the plug back in. There is an inspection hatch but half way down the tank so you need to empty at least 70 liters of diesel to open it. The lagoon is pristine clean so you may not lose any diesel overboard. You have a few items:

• a few buckets (one with a hole in)
• a dinghy
• rags and mosquito nets
• a garden hose
• clothes pegs
• rubbish bags

We took Saturday off to think this through (and lounge around and read and have fun). By Sunday we had a solution that seemed possible.

1. Empty one canister of diesel in to the broken bucket using a rubbish bag to stop the diesel escaping through the hole
2. Disconnect the outlet to the engine (after closing the stopcock)
3. Attach the garden hose to the outlet with a jubilee clip “borrowed” from the fresh water plumbing.
4. Use the dinghy pump to blow air back in to the tank clearing the blockage.
5. Run diesel in to the other bucket
6. Filter the diesel in to the canister using a mosquito net and a rag held in place with clothes pegs
7. Filter the diesel back in to the tank with net and rag
8. Repeat 5 to 7 until only clean diesel flows
9. Reconnect the engine to the tank and test.

And? It worked. There is no more dirt coming out of the tank and when we tested the engine it ran. A great Sunday!