Wednesdays and Saturdays

Clean as a Whistle

A distinctive feature found on Liberty ships is the steam whistle mounted high on its 

smoke stack that produces a deep resonant tone.  The sound generated by a steam 

whistle is created when steam is emitted through a circular orifice about 1/16 inch wide 

at the top of the whistle valve just below the bottom of a cylindrical bell housing.  The 

principal is the same as when a person produces a tone by blowing across the mouth of 

an open bottle.  All ships are required to have a whistle as a means of producing 

audible signals and warnings.  Now that most steam vessels have been replaced with 

diesel-driven ships, the electric horn has become the standard on most ships rather 

than the steam whistle.

On the Liberty ship JOHN W. BROWN the steam whistle is still used to make audible 

signals.  This type of whistle generally requires little maintenance.  It is designed to 

operate in all weathers and has few moving parts other than a steam valve and a 

linkage so the valve can be operated remotely by the watch officer from the conning 

station.  However, when the midships house was painted recently, paint got into places 

where it wasn’t intended in the ship’s whistle.  


The flexible sections of the operating linkage where it passes over pulleys is made of

linked chain similar to bicycle chain.  The painted chain links made them stiff and

prevented their movement over the pulleys


The steam orifice at the top of the valve was completely obstructed by paint so the 

steam wouldn’t flow through it.  In short, the whistle wouldn’t work.

To restore its operation, the offending paint was removed from the flexible portions of 

the operating linkage.  New fittings were fabricated at the ends of the chain segments 

and they were joined to lengths of stainless steel wire made from old sailboat stays to 

restore the flexible linkage.  Up on the stack, the heavy cylindrical bell housing of the 

whistle was removed to expose the steam opening and remove the paint from it.  The 

whistle was then reassembled and tested.  After adjusting the height of the bell housing 

above the top of the steam valve to achieve the desired deep resonant tone

characteristic of Liberty ships, the whistle was back in operation.  

This is just another interesting task in maintaining a 73-year old Liberty ship in operating 


Project Liberty Ship, Inc is a 501(c)3 non-profit, all volunteer organization engaged in the preservation and operation of the historic ship JOHN W. BROWN as a living memorial museum. Gifts to Project Liberty Ship are tax deductible.

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