Ball Watches were originally created for use by engineers in a harsh railway environment. Today, the watches are still being designed and made to work in those conditions. Our subject review is the Ball Engineer Hydrocarbon AeroGMT: a watch which carries a toughness badge to absorb impacts of up to 7,500Gs, antimagnetic resistance of 4,800 A/m, water resistant to 300m and equipped withTritium gas discharge microtubes which are claimed to be 100 times more effective than SuperLuminova and whose lume lasts 25 years.
But first to answer the curious question…what is the lume, we explore the various methods used by watchmakers to make the dial and hands visible in the dark.
What is lume?
The subject is interesting as it has technical as well as perception implications. Scientifically, luminance of an object can be measured and quantified on an absolute scale. However, the way we perceive an object, in the case of a watch typically we mean the hour markers and hour/minute hands to be luminous, and judge its level of brightness depends on the relative brightness of the surroundings it is in. In a dark surrounding the lume pops bright, but in sunlight, it is all but invisible. More information can be found in this article we link here.
Early attempts to make luminous dials were with radioactive materials mixed into pigments.
Radium-based luminous paints are one of the earliest. Radium was mixed into the pigments and painted on the markers and hands. Radium paint used zinc sulfide phosphor, usually trace metal doped with copper (for green light), silver (blue-green), and more rarely copper-magnesium (for yellow-orange light). The phosphor degrades relatively fast and the dials lose luminosity in several years to a few decades, despite the long half-life of the Ra-226 isotope (1600 years). The toxicity of radium was not initially understood, and radium-based paint saw widespread use in, for example, watches and aircraft instruments. During the 1920s and 1930s, the harmful effects of this paint became increasingly clear. A notorious case involved the “Radium Girls“, a group of women who painted watch dials and later suffered adverse health effects from ingestion.
SuperLuminova is a common material used to produce lume. Super-LumiNova is based on LumiNova pigments, invented in 1993 by Nemoto & Co., Ltd. of Japan as a safe replacement for radium-based luminous paints. The method, called Photoluminescence, produces the lume is by a type of phosphorescent pigments in the paint. The phosphorescent pigments need to be charged by exposing to an external light source (like a lamp or sunlight) and will produce luminance. This lume will last anywhere from 2 to 9 hours, depending on the thickness of the applied paint.
Tritium is another material which is used. Tritium (H3) a radioactive gaseous isotope of hydrogen with half-life of 12.32 years that emits very low-energy beta radiation. The devices are similar to a fluorescent tube in construction, as they consist of a hermetically sealed (usually borosilicate-glass) tube, coated inside with a phosphor, and filled with tritium. MB Microtec, who makes the Trigalight used in the Ball is one of the best manufacturers of this type of tubes. MB Microtec originally made thesetubes for military use, but were first approached by Luminox to produce the tubes for watch use. The success of the Luminox’s “Always Visible Technology” meant that it soon was adopted to be used in other watches. Traser, a watch company set up and owned by MB Microtec also uses the technology.
The Ball Engineer Hydrocarbon AeroGMT
The dial layout is designed for flight crew and air traffic professionals, and features a very large bi-directional rotating bezel. Markings are superbly clear and legible, and the large sword like hands make reading the tiime easy. A GMT hand in an arrow profile allows a second timezone to be read, and in combination with the rotating bezel, a third timezone is possible. A system much like the Rolex GMT Master.
However, a Deployant friend who is an air traffic controller told us that this is a rather romantic notion of how they work. Most air traffic contol centres are no longer darkened, and the controllers only use UTC for timing, so there is no need for a watch to display multiple timezones. Like many modern professionals, they also work in a data filled computerized environment where accurate time data is always available on screen.
The watch incorporates, for the first time uses Trigalight H3 micro gas tubes in the chassis of the bezel. All previous implementations for the Trigalight tubes have been on the dial. The Trigalight tubes are integrated into a self-illuminated 24-hour GMT bezel. Twenty five tritium tubes are integrated beneath the sapphire crystal of the bidirectional GMT bezel. As this is the first time tritium has ever been used in a timepiece outside the dial, it required US regulatory inspection and approval. An additional 18 tritium tubes are fitted into the hour, minute, second time zone hands and dial. A total of 43 tubes are used.
In comparison, Luminox uses a combination of SuperLuminova (on the dial and the 20 minute countdown bezel) and Trigalight on the dial in their ColorMark Nova.
The claim by Ball is that in the darkness of an aircraft cockpit or air traffic control centre, the bezel is 100 times more luminous than luminous paint like SuperLuminova.
The case itself is a very robust stainless steel case, measuring 42mm in diameter with a case height of 13.85mm.
The signature and Ball patented crown protection system ensures a sealed system. In practice, we find this a rather curious feature. It is a talking point and though undoubtedly it works, it is a bit cumbersome to have to release the crown guard before unscrewing the crown to set the time or to manually wind the watch. For water resistance, a triple lock screw down crown like those used by Rolex and other dive watches suffices to provide a good seal and practical usage.
Perhaps the crown protection system is essential for shock protection of the crown.
The caseback is closed, for a Faraday cage like device like a soft iron case is implemented to provide the high antimagnetic abilities. Within beats the Ball RR 1201-C, which is an unmodified ETA 2892-A2 providing hours, minutes, sweep seconds, date and second time zone (GMT) on an automatic movement with a power reserve of 42 hours. This is a robust, very reliable movement which is suitable for the technical specifications called for in this watch. This also ensures the movement is easily servicable in the field.
A nicely made butterfly style triple folding deployant buckle is fitted and allows the watch to be fitted over one’s aviation apparel. The watch is also available with a rubber strap with a standard pin buckle.
We find the height of the crown guard and crown to also affect comfort when the wrist is cocked, but otherwise the watch sits comfortably on the wrist and feels very solid.
The first impression on handling the watch is one which evokes a feeling that it is hewn out of a solid piece of stainless steel. Indeed it is, the case is machined from a solid block of hydrocarbon steel. We assume it is a standard 316L Stainless Steel, but as Ball documentation does not state. The watch is very well made, and the rotating bezel moves in both directions with satisfying and assuring clicks. The crown protection system, as we noted is a little gimicky perhaps, is well machined, and operates without glitch.
The dial and bezel design is bold, clear, legible. And we feel it achieves its aim of being used in an aircraft cockpit or air traffic control centre very well, notwistanding a romanticized notion as we mentioned. In the darkened environment, it serves brilliantly (pun intended) as the Trigalight tubes does a magnificent job in making the markings easy to read.
Retail price is S$4,500 with GST for the version with the stainless steel bracelet, and a little less for the rubber strapped version. We reckon this is rather well priced for a watch of this caliber: COSC certified movement, three timezones, excellent lume in a well made and engineered case.