WW II U.S. Navy Mark I Deck Clock
Chromium Plated Brass

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Naval Observatory Cartouche 1939 Fully Restored Presentation Quality!


The WW II Chelsea MK I Deck Clock’s case was made differently than the ubiquitous Seth Thomas version. It is more refined and far better looking in this unique chromium plated forged brass case.

DIMENSIONS: 5 1/2″ Diameter of face 3 1/4″ Deep
7 1/4″ Full Diameter Weight 10 lbs 6 oz

Presented is a fine Chelsea chromed brass cased clock completely restored example, back winding, WW II, Navy MK I Deck Clock with a hinged front that is complete with two backing plates. One of these plates acted as a water tight cover and shock absorber and the other mounts the case to a bulkhead or wall. It is rare to get these clocks with their back cover plate and finding one with the original mounting plate is an even rarer exception. The Chelsea version of what was a supposedly standardized mil-spec design is more refined and has a different hinge arrangement than the thousands of nickel plated clocks that were made by Seth Thomas. It has been recently serviced by a clock smith who specializes in military ship’s clocks. It is keeping very good time compared to a quartz comparison watch. Navy MK I DECK clocks of WW II were manufactured in accordance with military specifications 18C-11 and 18C -13. This Chelsea example has modifications which are unique. The front section holds the movement and has an integral stud on the backing plate that acts as the hinge. This compares to the more common Seth Thomas version which uses a removable pin, and has a nickel plated case. In both designs, the back of the front section has all the controls on the rear.
The Navy MK I Deck ClockThe Navy MK I Deck Clock
MK I hinge
Both Andrew Demeter in his definitive book, “Chelsea Clock Company, the first
100 years” and Marvin Whitney in his encyclopedic work, “MILITARY TIMEPIECES” say that these
clocks were chromium plated up to 1941 when cases were switched to Bakelite, a phenolic. It is our opinion that they
were nickel not chrome plated.
Back Mark I Deck clock made by Chelsea is a rare find, as is a clock of this age and service at sea to be found in this fine condition. It is perfect for a collector of military pieces or as an important gift.
Detail of controls Beneath the hand arbor is etched: MARK I DECK CLOCK
(NO) 839  1939(NO)represents the Naval Observatory
which means the clock not only met the military specifications, but also met the stringent standards of this institution which
maintains the Nation’s Time Standard. At the bottom of the dial it is marked Chelsea The following controls are accessed on the back: Fast – Slow adjustment. To regulate
turn towards S to Slow and vice versa Stop – allows for
precision setting with master clock Set – moves hands                    Winding Arbor

It has a Chelsea Model 17K,
11 jewel 8 day movement that is wound, set and stopped through a slotted dust cover at its rear which closes. A separate
start/stop mechanism allows it to be synchronized with a master time piece. The removable vibration
dampener backing plate is attached to the bulkhead plate by six screws and holds the front case secure by a wing nut dog.
side viewside view

side viewSides and Back view

CONDITION: This example has seen about 81 years of service, much of it at sea, but has the appearance of being almost new. The face is in excellent condition, the lens is clear with some small abrasions when viewed close-up. The dots over the numbers are still painted with irradium for night viewing. This is usually removed because it was radio active. The movement has been recently serviced by a clock smith that specializes in military ships clocks and is keeping good time. A key is included.

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The cost of shipping, packing, handling, and insurance to your destination, will be calculated point to point and is an additional charge. You may email us to get these costs. We price our shipping honestly, but we expect to be reimbursed for the nominal cost of packaging materials and handling.

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Established in 2003

Celebrating 18 Years of Exellence in Nautical Antiques

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