P6500 Navigators / Analog : Permanent Light

Product Information

P6500.405.33
Navigators / Analog
Permanent Light Technology in military watches

Waterresistance: 30m / 99 ft
Case material: polyamide
Crystal: mineral
Strap: textile (MIL-S-46383)
Case size: 45mm
Art.Nr.: P6500.405.33.01

MIL-W-46374F-TYPE 6
6645-01-364-4042
MILLICURIES-UNDER 25-3H
TRASER P6500.405.33.01

Gaseous Tritium Light Sources (GTLS)

H3 is the original military watch with the unique Permanent Light Technology. This means there is no need to hold a H3-watch up to the light and you won´t need to press anything to see it.

This technology was, for many years, classified top secret and only available to active military personal.

H3-watches are the current issue watch for the US Navy Seal Teams and more than 300,000 US military personnel currently utilise this unique timepiece. Chosen by the world´s elite military units, including the SAS, SBS and the French Foreign Legion; H3-watches prove themselves in missions throughout the world!

The technical term for the unique H3-light is a Gaseous Tritium Light Source (GTLS).

These low level light sources have unique properties, they are unaffected by water, oil and most corrosive materials an require no external power source or exposure to light in order to work. Quality control is the dominant consideration in the labour intensive manufacturing process H3-watches go through. They are 100% inspected for dimensions, brightness, temperature, thermal shock an Tritium leakage. Random sample testing is performed continually for discolouration, brightness decay, reduced pressure an vibration effects. They remain fail-save and maintenance free and have a useful life in excess of 10-20 years.

Permanent Light Technology in military watches - Brilliance for American military watches

Excellent readability in the dark – proven in action in the first gulf war
Since 1989 the American army has specified the use of tritium gas light sources for military watches destined for troops, in order to ensure that they can be read in the dark. Among the best-known and popular models are the SandY 490 Type 1 and the SandY P 650 Navigator. Their unsurpassed lighting system is based on permanent light technology. The light sources for these watches are produced in Switzerland; mb-microtec is the only company in the world which manufactures these light elements in miniature format. But still, quite a few obstacles had to be overcome before the first watches could be supplied to customers.

The security officer on duty in the New Cumberland Army Depot, Pennsylvania, could hardly believe his eyes when he saw the measurements being registered on 12 April 1988. The Geiger counter in one of the storage halls had reported considerably increased radioactivity. The cause of the contamination was quickly found: the SandY 184 military watches in the hall were emitting an unusually high dose of radioactivity. The hands and markings on the dial were coated with traditional tritium phosphorescent paint. In the case of some watches, one hundred times the 50 dpm registered in the past and considered safe were measured. The large stock of watches in New Cumberland was therefore a security and health risk. The security officer immediately informed the relevant military department in the Department of Defense.

The solution
Thomas Chleboski, Head of the Standardization and Specifications section in the army, acted immediately and deleted the supplier Stocker&Yale from the Qualified Product List QPL-46374, the list which states which companies are qualified to supply wrist watches to the U.S. Army.
The news was quite a shock for Jim Bickman, President and CEO of Stocker&Yale in Beverly, Massachusetts, as his company had profited from several lucrative orders for SandY 184 in the previous four years. But Bickman had an idea as to how a real solution could finally be found to the problem of radioactivity in watches. For several years his company had been supplying the army with compasses where a small glass tube filled with tritium gas was used for illumination. The tritium gas light sources produced by the Swiss company mb-microtec in Niederwangen with the help of a special laser were proven not to release any radioactive material whatsoever. Could this groundbreaking lighting technology not also be used for watches? However, in order to make this possible, the Mil-W-4637 specification relating to the manufacture of military wrist watches would have to be changed. "So I decided to convince the relevant departments in the U.S. Army to create new specifications for the production of military watches. I wrote a draft version of this modified product specification myself", remembers Jim Bickman. That was the hour in which a completely new generation of military wrist watches was born.

Intensive cooperation between America and Switzerland
mb-microtec, the only manufacturer of these tiny tritium light elements in the world, also signaled great interest in launching such a watch. The two companies, who had been business partners for many years, quickly reached agreement: huge efforts should be made to produce some prototypes of watches using the new system. These sample watches were produced in Switzerland, were all SandY watches had been produced since 1984 by general contractor Montres Constructa S.A., Bettlach. Another member of the well-established team was the company Terna S.A. Fabrica Orologi in Mendrisio, where the individual components such as plastic casing, movement, dial, hands etc. were assembled.

Use of Tritium gas light sources
On 31. May 1989 the new Mil-W-46374E officially entered into force in the U.S.A. This standard not only brought about the change from tritium illuminated paint to light sources with gaseous tritium (so-called Tritium vials). In connection with the use of the new light system, the dial and the hands of the military watch were completely redesigned. New on the dial was also the symbol for radioactivity as well as the marking H3. Very strict requirements had to be fulfilled with regard to the tritium gas enclosed in the glass tube, the light elements were not allowed to contain more than 25 millicuries of H3. And no radioactivity whatsoever might be measured on the surface of the watch.
The light system consisted of sealed glass tubes filled with tritium, whose inside wall was coated with a fluorescing substance. Today, this light system, which cannot be bettered in terms of brightness is also called Permanent Light Technology (PLT) or TRASER.

Development of prototypes for qualification tests
According to new regulations, military watches should in future be provided with tritium gas lighting elements. But a few months had to pass until this stage was reached. Before a supplier is even allowed to tender for a military order, he has to submit qualification samples of finished watches, which are then subjected to a series of extremely rigorous tests by the Department of Defense. Only when these tests have been successfully completed is the product included in the Qualified Product List. Therefore development of such qualification samples is work done on trust, without any guarantee that an order will follow. However, Stocker&Yale and their Swiss partners were confident that they would achieve the qualification.
In the second half of 1989 therefore, work proceeded apace in Switzerland on the development of the necessary qualification samples of watch models SandY 490 Type 1, Type 2 and SandY 590 Type 3, which had to fulfill both the strict requirements of the U.S. Nuclear Regulatory Commission (NRC) and also the new military specification. Finally, the prototypes were successfully tested in 1990 and accepted in 1991 as military equipment by the Department of Defense.
Types 1 and 2 are models with a plastic housing and mechanical movements which had to be accurate up to a few seconds per day. Type 1 also had to have at least 15 jewels. Type 3 was a battery-driven quartz watch with much greater accuracy, only allowing deviations of a few seconds a month.

The start of a marathon
But the competition was close behind. The Marathon Watch Company Ltd. in Canada was also seeking qualification for one its products within the framework of the Mil-W-46374E specification. In the same way as Stocker&Yale, Marathon had already been supplying the U.S. Army for many years. The Canadians also had their military watches manufactured in Switzerland: at the beginning by Gallet S.A. and later in their own company in La Chaux-de-Fonds. In autumn 1989 Gallet ordered tritium light devices for Marathon watches from mb-microtec and inquired what adhesive was most suitable for fixing to the hands. However, the delivery was only received in February 1990, as Gallet did not yet have approval for the processing of light devices with gaseous tritium.

The first gulf war suddenly created demand
The first gulf war broke out in January 1991, and the U.S. army suddenly needed larger numbers of watches for the troops stationed in the gulf. Which of the qualified manufacturers was in a position to supply the new military watches first and in the necessary quantities? There followed a neck-and-neck race between Stocker&Yale and its Canadian competitor Marathon. Marathon crossed the finishing line first and gained the first order for 60,000 watches manufactured according to the new production specification. Marathon offered earlier delivery than its American competitor. "It is not easy to win orders for watches. But is a disgrace to lose them. I tried to fight the decision and pointed out that the delivery date was not realistic", commented Jim Bickman. But in vain. Marathon managed to retain the order and to implement it at the beginning of April. The first Marathon 348 Mil-W-46374E Type 2 cost the army around 50 U.S. Dollar each. Naturally, the light elements for these first watches supplied to the troops came from mb-microtec. Somewhat later, Bickman's company received an order for the high-quality, olive-colored SandY 490 Type 1.

Navigator – the watch for special units
In October 1991 the manufacturing specification for military watches was again updated by the authorities. Mil-W-46374F now allowed production of a watch model Type 6. A wrist watch of this type had to fulfill additional requirements with regard to altitude, magnetic field protection as well as salt spray and perspiration resistance. In addition, the watch had to withstand the low air pressure at 35,000 feet for at least 60 minutes without sustaining any damage. Its magnetic protection rating was raised from 15.5 to 125+/-1 Gauss. This means that the antimagnetic watch will not cause mines to detonate. Stocker&Yale qualified with the SandY P 650 Type 6 Navigator, a quartz watch with a black plastic housing and rotating GMT lunette. Marathon Watch brought the Marathon 211 Navigator, also with plastic housing, onto the approved army product list.
But also the Type 1, 2 and 3 – SandY 490 and SandY 590 – continued to be manufactured under the new specification. As from 1991 Stocker&Yale were able to secure smaller orders from the army; first for 500 SandY 590 Type 3 and later for larger volumes of up to 10,000 watches per order. Finally in
1994 came the first order for 14,000 SandY P 650 Type 6 Navigators, which were supplied to American troops the following year. It then became part of the standard equipment of special units such as the Army Rangers, Army Special Forces («Green Berets»), Navy SEALs (Sea, Air, Land), and EOD (Explosives Ordinance Demolition) Teams. In 1999 and 2000 further orders were placed for this classic watch. The Navigator was and is very popular with the troops and is also one of the most desirable collector's items for those who collect military memorabilia. It is particularly popular with collectors who like to actually wear the watches themselves. The Swiss company Traser-Watches has relaunched the classic Navigator his year: the MIL-W-46374F Wrist Watch Navigator P 6500.

Over 1 Million SandY military watches in use
In November 1999 the new "Performance" specification of the MIL-PRF-46374G standard was issued. since then, tritium light devices are no longer an absolute requirement with regard to good recognition of the time in the dark.
Orders from the Departments of Defense have clearly decreased since then. In 2000 Stocker&Yale withdrew from the military watch and compass business and sold this division of the company to Cammenga & Associates, Inc.
Between 1980 and 2000 Bickman's company won many tenders for the U.S. army and supplied around 1 million watches. And at the same time around 500,000 timepieces were sold on the civilian market.

The SandY 490 Type 1 was the first military watch from Stocker&Yale which was supplied with Permanent Light Technology.

The SandY P 650 Type 6 Navigator – the "King" of military watches. Its nighttime illumination cannot be bettered.

Price: $239.99

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