Main and Auxiliary Engines

Main Engines

Two Main Engine (Winton 158-6)Winton model 158-6 six cylinder direct drive engines.  Rated 670 HP @ 450 RPM. Four stroke naturally aspirated cycle, 14" bore X  16" stroke, direct drive with sliding camshaft for reversing, with eight cams per cylinder --  separate ahead and  astern cams for intake valves, exhaust valves (water cooled), fuel injector and starting air.

Injection system is common rail, with a two cylinder high pressure (HP) pump feeding the injectors, accumulator bottle and gauge.  Speed is manually controlled by two levers, one rotating an eccentric linkage on the HP pump suction valves (thus varying the effective stroke of the pump), and the other operating a set of wedges that vary the lift and duration of the injector spray valves.  A large wheel slides either the ahead or astern cams under the rocker arm rollers.  One more lever opens the starting air control valve.


The original 15 KW generators were powered by Winton three cylinder diesels, similar to the radiator-cooled one shown.

Original three cylinder generator engine (Model 176-3)

Also used was a combination 5 KW generator and air compressor.Combination 5 KW generator and starting air compressor

Around the beginning of World War II, the Coast Guard refitted Calypso, installing heavier armament.  She now had a 3"/50 main gun, and two 20 mm antiaircraft guns, along with a rocket grenade launcher and depth charges.  With all the new equipment, including a "sounding machine" and other primitive electronics, bigger generators were required, and the main switchboard was upgraded.

Today, Circle Line XI still has that same old switchboard, with three 30 KW 120 volt DC generators each powered by a GM 3-71 diesel running at 1200 RPM.  Because sightseers want hot dogs and cold beer, AC power was added by Circle Line to power the snack bar, PA amplifier and the new fluorescent lighting.  Though the pumps and other machinery as well as all of the incandescent lighting all run on DC to this day, a GM 3-71 powering a 35 KW 208 volt three phase AC generator provides "modern" power as well.  Four Allis-Chalmers 4KW DC to AC motor-generator sets provide backup in case of AC generator failure.

The 400 PSI starting air was pumped up by two Ingersoll-Rand (Type Twenty) two stage (with inter- and after- cooler) air compressors, of which one remains (the other one was replaced by a modern compressor due to excessive corrosion).  The compressors, like the main engines, were originally sea water cooled, but fortunately the main engines were converted to fresh water cooling early in their lifetime so they did not corrode as much.  The compressors are each powered by a Westinghouse 12-1/2 HP 120 volt DC Motor.

A pair of two stage centrifugal pumps each powered by a 10 HP Diehl DC motor provide firefighting water, and another 10 HP Diehl DC motor powers the electric prelube and backup oil pump for the main engines, which each have two reciprocating lube oil pumps in a dry sump system.

The Sperry steering system has a 5 HP DC motor driving a cable drum in the engine room, with a direct shaft connection with the pilothouse for emergency backup.  The cables lead back to the steering compartment quadrant, with twin rudders behind the 62" by 53" propellers.  An emergency tiller can also be rigged in case of steering cable failure.

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Copyright © 2002, Brian Bailey, W4OLF
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