Cambridge City Hall Tower Clock Restoration
1994-1995

Description of Clock: 1892 E. Howard double 3-legged gravity escapement; hour striker. Approximately 5 feet long, 6.5 feet high, 2 feet wide. Pendulum: 14 foot long zinc tube temperature compensating. 4 dials: each approximately 8 feet in diameter.

Condition prior to restoration: The original hand wound-pendulum regulated mechanism had fallen into disrepair and had been replaced by 4 electric movements in 1957. Electric movements were no longer functioning.

Missing E. Howard clock parts included:

1) ALL components of the double 3-legged gravity escapement (46 parts).
2) ALL components of the 1 to 12 dial gear reduction assemblies (48 parts).
3) The third shaft in the time train, including a steel pinion and a brass 5 spoked gear.
4) ALL components of the motion works between the planetary gears and the dial gears (80 parts).
5) Striking linkage and half-turnbuckles.
6) 1 bell axle support roller assembly.

Condition of remaining parts: Some were broken, but repairable, ALL had suffered badly from rust, corrosion, and pigeon droppings. The original paint was ruined, although the floral design and pin striping were faintly visible. The unusual fail safe weight systems were covered with rust, internal parts were ruined, weight cables were broken, pulleys were rusted or missing. The striking hammer mounting timbers were rotted and the securing bolts were severely rusted. The remaining bell support roller assembly was severely rusted. The remaining bell support roller assembly was severely rusted and nonfunctional.

camb1
Before Restoration
MORE PICTURES

camb2
Restoration Completed
MORE PICTURES
Summary of Work Completed:

1) Restored the E. Howard mechanism (both time and striking trains) to its original hand wound/weight driven/pendulum regulated operation. All missing parts were constructed to match the appearance and function of the original Howard parts. Close to 200 parts were precisely fabricated and installed.

2) Thoroughly cleaned, buffed to a gloss, and lacquered all shafts, gears, and bushings.

3) Duplicated the original paint scheme, including gilt flowers and pinstriping.

4) Constructed and installed 4 sets of hands of straight grained redwood - gilded with 23 carat gold.

5) Restored, gilded, and installed 4 sets of lead alloy numerals and minute markers.

6) Repaired and restored both fail safe weight systems and weight tracks.

7) Constructed and installed 2 new bell axle support roller assemblies.

8) Designed, constructed, and installed a device which turns off the striking of the bell from 11 pm through 7 am.

Currently: This beautiful machine is keeping time and striking the hour with an accuracy of approximately 1 minute per week.