"One moment," I broke in. "Back in 1919 the destroyers of the 'flotilla leader' class had thirty-thousand horse turbines."
"Ay," said Munroe, "I've rattled roond in them."
"If I remember rightly, they were three hundred and fifty feet long and did thirty-five knots," I continued. "They carried two hundred and eighty tons of oil fuel. That was enough for eleven hours at full speed, or three hundred and eighty-five miles. That is, they used twenty-three tons of fuel an hour."
"Mon, your memory's fine," assented the Chief. "Ye'll well remember they could dae fifteen knots for aboot a hunder and sixty hours on the same fuel, using maybe less than twa tons an hour.
"But yon's better engines. The laddie that designed them did a wairkmanlike job. For an Englishman they're no sae dusty. But we're getting out a set on the Clyde that'll make him sit up.
"Fifteen tons of oil fuel an hour they eat developing full power. She steps along at three hunder knots. Forby we tank seventy tons, it's enough for four hours and a bit, and that'll be fourteen hundred miles. But the Skipper dinna drive her at that, thank the Lord, for the bed-plates are a bit light for my immediate liking. Twa hunder's our cruising speed. That takes only three tons an hour and gies us maybe four thousand six hunder miles."
He opened a door in a bulkhead and showed me a small room. It was very bare. There was a small bucket-seat, a row of levers and a board covered with indicators.
"Yon's whaur the fireman sits," explained the Chief. "He holds the steam at six hunder poonds preesure and superheated to four hunder and seventy degrees. That's aw there is tae it."
He poured into my entranced ears the way the steam was made. The fuel tanks were below the second deck. The oil was pumped up to hot pipes and vaporised, and was then blown under pressure from a row of nozzles upon the generator tubes. The Janes Fluid flashed into steam somewhere in the tube, nobody knew just where. It boiled at 20 degrees below water and the super-heating gave it a tremendous expansion.