A look at the official Technical Specifications & Requirements Development Memo for the Martin M-130 Chesapeake Collection Chronograph. By the managing designer and engineer prior to manufacturing in 2018.
Management Hartwig Balke & George Thomas
Engineering Hartwig Balke
Design Hartwig Balke & Patrick Ayoub
Assembly + Calibration George Thomas
Manufacturing Partners Ickler GmbH ,Cador GmbH, Estima
It happened to be Memorial Day when Hartwig was walking from the domestic to international terminal at BWI Airport when he noticed a pop-up display of some antique cockpit instruments in a glass case. They were accompanied by framed articles describing the Martin M-130 “China Clipper”, the historic aircraft that opened the skies above the Pacific to commercial flights. It was a plane that shrunk the world, skipping across the Pacific like a rock across a pond in an astonishingly fast sixty hours. This " flying boat" was built right in our backyard here in Maryland.
As an engineer from Germany, the story of the “China Clipper” was inspiring to Hartwig as he learned of yet another monumental industrial achievement that happened to occur right in his new backyard in Maryland. Nonetheless, what captivated him over anything in the pop-up display was this one particular 24-hour cockpit clock. It featured a striking contrast between the luminous numerals and black background. Its identity as a “tool” was clearly communicated, but at the same time, its purity carried a distinctively contemporary and appealing aesthetic.
This spontaneous moment at the airport instigated years of playful experimentation and casual visations to the Glenn E. Foundation, which housed many of the “China Clipper’s” artifacts. Ultimately, it produced our signature pilot chronograph made in collaboration with commissioned restorers of the precious cockpit artifacts Hartwig saw at the airport.
Before boarding his plane back home to Germany, Hartwig snapped a quick photo of the cockpit instrument and proceeded to play around with it on photoshop for the following weeks. When he returned to the TWC workshops weeks later, he came prepared with a completed digital rendering of the original clock dial encompassed by a Potomac case. In addition, he printed out the dial onto a piece of cardboard and placed it within the physical steel case. The makeshift prototype showed instant promise. It was time to start digging deeper into the details.
- Movement purchase - Movement components are in TWC stock. Assembly must follow ETA standard requirements)
- Case: After finished drawings and final study, prototype required. First case prototype March - April 2017.
- Dial: After final study detailed drawings are required in order to make the first prototype. First dial prototype February - March 2017
- Hands: Delivery time has to be checked in order make the tool for the final design of hands. For the assembly of the prototype off shelf hands can be used.
- Watch: The first prototype of the watch has to be ready April 2018.
The Martin M-130 is designed as a sports watch, it should be an attractive timepiece for an active, sports oriented, successful person with style. The watch should attract attention when visible. The watch should be an everyday item as well as being a timepiece that expresses the owner’s dynamic lifestyle and good taste for the extraordinary.
The chronograph has to be clean and easily readable at night time. Hour, minute, and a constantly rotating second at 9 o'clock position. The stop function has a sweep second operation from the center, a minute counter at 12 o'clock and an hour-counter at 6 o'clock position. The chronograph should have Arabic numerals in a good readable contrast to the black dial background. The hour markers are dots with a luminous layer, at 12 o'clock is a luminous filled triangle to mark the 12 o'clock position at night time. The minute and hour hand are designed after the hand of an 1935 aircraft instrument. Recommended diameter 42mm, thickness 14.5mm. available.
The watch case has to be in stainless steel. Edges need to be smooth and clean without losing too much of the original shape. Lugs need to be bent down in a way that smaller wrists are able to wear the watch comfortably and that end parts of the leather strap are still visible when looking straight down onto the face of the watch. The width in between lugs should be 20mm in order to install standard leather bands of different materials. The leather bands should be equipped with a single folding deployment clasp. The bezel should have a grove similar to the skipjack bezel, slightly bigger in diameter than the case mid-section. The watch should have a domed scratch resistant sapphire crystal and should have a two sided anti reflex coating. The back is closed and should bear the image of the China Clipper/Martin M-130 and customer important information such as the Ref. No., Serial No. ATM - rate and manufacturer’s name.
Technical Requirements : CASE
Case Material: stainless steel, sapphire crystal (Two side anti reflex coating) at the front
Dimensions: Diameter 42mm, dimension between lugs 20mm, height 14.5mm
Three main components - Bezel, Midsection with lugs, caseback
- All three sections are screwed together. Bezel screwed, case back screwed onto midsection by 5-6 screws. Lugs are machined, Surfaces between bezel / midsection and case back / midsection are sealed by o-rings.
- Crown with standard tube.
- Caseback with etched image of the China Clipper and customer important information such as 5 ATM, Serial No., Reference No., USA, Towson Watch Company.
Mounting of the Movement
- dial and hands are executed from the front. Mounted bezel secures dial in vertical and horizontal direction. Winding stem secures movement from rotating. Movement secured through mounting plates (Briden) and screws to the case midsection.
- Screws for the back have to be placed and distributed in a way that a 5 ATM water resistance is guaranteed.
Technical Requirements : DIAL
Dial Material - brass
- Thickness - 0.5mm
- Numerals printed.
- Dial background blasted in order to create a nice smooth surface. Minute circle printed, hour markers with luminous in the same color as numerals.
- Date window should be at 9 o’clock in black background with red date number
- Dial feet diameter, location and length depending on movement Caliber 7750.
Technical requirements - HANDS
Material - steel or brass.
- Surface painted in the color according to color code Pantone 458U.
- The profile of the hands should be flat
- The center arbor should be in black.
- The hands should be skeletonized, the back of the window should be filled with super luminova Pantone 458 U. Actual shape of the hands see PS-image.
Sweep second should be painted according to Pantone 3265U. Length 0.5 mm longer than the minute hand.
Arbor of the sweep second hand should be made from a softer material (brass) to be able to ream the seat according to shaft dimension.
Arbor and hand should be riveted together in a way that orbor does not turn during the reaming process.
Technical Requirements : MOVEMENT
The movement needs to have 7 main functions - hour, minute, center chronograph, second.
Minute counter at 12h, hour counter at 6h, constantly rotating second at 9h and a calendar disc.
The movement will be the self winding 1314 lines in a finish acc. to the Decor Code # 10 N/D/R in rhodium finish.
Assembled in accordance to ETA Caliber 7750 standard requirement information.
Dimensions are 30mm, height 7.9mm according to ETA drawings.
Rotor should be engraved with the TWC Logo in the middle of the rotor. Left from the logo has to be the word Towson and right from the logo Watch Co. engraved in New Times Roman as shown on TWC drawing (sketch).
All visible screws need to be blued.