The Engine Room

Good afternoon. I'm Kevin Simpson, Chief of Security aboard Star Sapphire.

Once upon a time, Engine Room tours were a possibility for passengers, though never a guaranteed probability.

These days, our Engine Room is offlimits to all but officers and crew who have a reason to be there. Consequently there are no pictures of our vessel's Engine Room, and a tour is definitely not on the books.

I can, however, tell you a little bit about what keeps us going.....

General Description of Propelling Machinery

Our propelling machinery was constructed by Vickers-Armstrongs and, at the time it was originally installed, incorporated the latest in high speed turbine and watertube boiler design. 

There are two sets of Vickers-Armstrongs Pametrada double-reduction geared turbines, with a combined output of 27,000 Shaft Horse Power in service, and 30,000 Shaft Horse Power maximum.

Each main turbine unit consists of an HP and an IP turbine, driving its own pinions at 4,195 rpm and 3,425 rpm, respectively. They take steam at 600 il PSI, 850 degrees Fahrenheit, and operate on a reheat cycle. The HP exhaust is reheated to the initial temperature, and before it enters the IP turbine, the steam passes through two groups of nozzles. There is also an overhead port which bypasses the first three stages. One of the nozzle groups is controlled, and the arrangement is such that steam is not available at the overload valve unless the nozzle control valve is open.

Steam is supplied by two oil-fired Foster Wheeler controlled superheat boilers and one oil-fired Foster Wheeler reheat boiler. 

The propelling machinery is located slightly aft of midship. The arrangement order, forward to aft, is: boiler room, auxiliary machinery room, switchboard room, stabilizer compartment and refrigerating machinery.

Our two four-blade propellers are solid cast manganese bronze. Their diameter is 17.25 ft, pitch 17.25 ft.

Electrical Power

Electric power is supplied by two DC turbo-generators (each with 750 kw capacity, 220 volts) for the auxiliary machinery and two AC turbo-generators (each with 750 kw capacity, 440 volts, 60 cycles) for ship's utilities. AC power is stepped down to 220 volts for small onboard motors and lighting. A 750 kw Caterpillar Diesel motor is on standby to supply additional DC or AC power and two National M4AA4 diesel generators, each capable of generating 75 kw DC, 220 volts, are on standby for emergencies.

Air Conditioning

Sapphire has 27 air conditioning units serving the public rooms, the ship's hospital, and passenger and crew cabins. Chilled water is circulated from a central refrigeration plant. The plant has 34 exhaust and 11 supply fans, and altogether the units run at 893 HP and discharge 34,600 cubic feet of air per hour.

Domestic Fresh Water

An Aqua Chem flush evaporator provides 120,000 US gallons per day of distilled water from sea water for all of the ship's needs. This distilled water - which we mineralize and chlorinate - is excellent for drinking and for all domestic uses. 


Sapphire has been fitted with two Denny Brown stabilizers which can reduce a roll of 18 degrees to one of less than 6 degrees, contributing greatly to passenger comfort. Two fins, one on either side of the vessel's hull, below the waterline, counteract the rolling movement of the ship in rough seas. The stabilizer fins are automatically controlled by hydraulic pumps and Gyros to maintain their positions regardless of the ship's motions and wave action.


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