Time-Interval Bell Restoration
Part of the fire control system for the 14' guns

Not all of our project require heavy lifting and hundreds of man-hours to restore. From time-to-time its nice to take a break and do some detail work on some of the artifacts collected by the museum over the years.
 
The time-interval bell in the gun pit is just one component in the larger fire control timing system. In order to keep all the target spotters, plotting room personnel and gun crews operating at the same pace, a series of bells were connected to a clock like device that chimed a series of rings every thirty seconds. The purpose of this system was to act as a sort of pulse by which all components in the fire control system operated.
 
A bell was placed in the gun pit to let the gun crew know when the next command to fire was supposed to be executed.
 
While the museum has managed to salvage two of the original cases for the pit bells, both have seen considerable ware and neglect over the years. In fact

the bell cover in the Battery Osgood pit, has no less than three bullet holes in it.
 
The restoration process began by removing the galvanized steel cover from the cast-iron backplane, and removing the four nuts that held the box to the parapet wall. After the pieces were removed, the wooden board that mounted the actual bell inside the box was found to be in such bad condition that it just fell apart in my hands. Luckily, I was able to get measurements so I could fabricate a replacement.

Now that all the pieces were separated, it was a simple matter to media-blast all the metal parts to remove any rust and corrosion, minor sheet-metal work was done to the cover and two coats of automotive primer and high-gloss black pain applied. This should mimic the original finish as much as possible.
 
Now it was off to the computer to search for a suitable replacement bell. From measuring the inside of the cover I was able to determine that the maximum size bell that could fit in the case was about six inches. A vintage bell, similar to the type originally mounted was obtained from our old friend eBay.
 
Check back soon for future updates, this is an ongoing project.
 

Time-Interval Bell as mounted on the Battery Parapet

Photo showing  condition of the cast-iron backplane

The backplane has two brass screen vents at the
bottom to let the sound escape.

The Backplane shown on the workbench after sandblasting, primer, and  paint.

Backplane, Cover, and Mounting Board back from sandblasting and paint. The three are now ready for
a new bell to be re-installed.  

Continuing Projects