OW P-104 Selectron: ready to calculate

Some brands have appealed to me on paper without anything really coming of it once the watch was on my wrist. Ollech & Wajs does not belong to that club. I discovered the brand through the reissued C-1000, whose heritage, efficient design and uncompromising performance struck me straight away.

As the brand released new models, I harboured the wish of holding its watches in my hands and, perhaps one day, of meeting the man who brought it back to life, Charles Le Menestrel. One email, and the meeting was arranged. A few days later, there we were over a coffee, several Ollech & Wajs models laid out in front of us, including the OW P-104 Selectron. I had told him of my interest in this watch. Once on the wrist, that interest was confirmed outright. I felt what a screen never conveys, that impression of having something special on your wrist.

Coffee finished, Charles agreed to leave me the P-104 Selectron for a few days. A book on the history of the house completed the loan. Leafing through it, I discovered a strong connection with air and space. There was no way I could settle for my living room to get acquainted with this piece. So I took to the road, heading for the Clin d'Ailes aviation museum in Payerne.

A computer on the wrist

The Clin d'Ailes museum sits in a hangar, beside the Payerne air base. You walk between fighter aircraft of varying vintages. Their fuselages echo the steel that dominates the P-104. More than that, the propellers fitted to some of these aircraft call to mind the Ollech & Wajs logo, two letters merged into a propeller. 

The connection with air and space is not merely visual. Long before so-called smart watches, Ollech & Wajs was already offering a calculator on the wrist. The brand called it the "Selectron Computer", at a time when the word "computer" still meant the person doing the calculating, the human bent over their figures, rather than the machine. One period advertisement praised a watch of tomorrow. Another spoke of a "Swiss Flight computer".

The pieces that bore this name form a small lineage born in the mid-sixties. A first hand-wound Selectron Computer in 1966, an automatic OW Computer presented as a miniature instrument panel, then a chronograph powered by a Valjoux 7733 at the end of the decade. All shared the same purpose, serving those who flew and those who calculated, pilots, navigators, engineers. A two-thousand-word manual came with the watch, such was the range of operations it allowed, on the ground as in the air.

The museum devotes a room to Claude Nicollier, Switzerland's only astronaut, who went four times to where aviation gives way to space.

The P-104 Selectron has never left the atmosphere, but it comes from that moment when man calculated his trajectory by hand, bent over dials, before handing the task to machines. It belongs to that parenthesis, between sky and space.

Polishing forbidden

The case sets the tone, that of a tool without frills. No polished surface, no mirror finish to catch the eye. Everything is brushed. The front and back faces of the lugs bear a circular brushing, repeated on the screwed case back where the brand logo and the words Zürich 1956 appear.

The flanks adopt a horizontal brushing. This choice is not merely aesthetic, a brushed finish takes scratches far better than a polish, which betrays the slightest contact. The approach is consistent throughout, that of a watch made to be worn through every adventure.

As for figures, the P-104 Selectron measures 39.5 millimetres in diameter excluding the crown, with a lug-to-lug of about 49 millimetres. That last figure matters more to me than the diameter, because it determines whether a watch will sit well on the wrist. On paper, those 49 millimetres gave me pause. Yet once the watch was on my wrist, which measures around 18 centimetres, everything fell into place, the lugs not overhanging. They could, however, prove a drawback on the slimmest wrists.

The thickness of 13.8 millimetres, inluding the sapphire glass, is not insignificant. Owing largely to the very reassuring 300 metres of water resistance, it is nonetheless no handicap to comfort. The stepped profile of the case, coupled with downturned lugs, puts that thickness into perspective. The watch wears far better than the figures might lead you to fear.

One rare detail deserves attention. The lugs are drilled twice. A first hole, closer to the case, reduces the gap between strap and case, which suits a two-piece leather strap well. A second, further towards the tip of the lug, opens up more room for a nato or single pass strap of varying thickness.

That said, I had no trouble fitting the single pass strap supplied by the brand using the hole closest to the case. Even so, this double drilling offers a latitude one rarely encounters, and says a great deal about the care given to real-world use.

Visually strong, the screw-down crown continues the theme. Wide and thick, it affords excellent grip. Deeply knurled and signed with the O&W logo, it handles with assurance. It exudes quality of manufacture and assembly.

Some may regret the absence of a crown guard. There is no need to fear for it in the event of a knock, however. Its wide tube inspires robustness.

Finally comes the bidirectional bezel. For the first time, I have a friction bezel in my hands. Being someone who enjoys hearing the clicks when turning a rotating bezel, I expected to be frustrated. Not at all. The action is pleasant and precise. Above all, this friction system makes perfect sense here. Given the bezel's non-linear logarithmic scale, precisely engraved and filled in black, clicks would have made no sense, being linear by definition. Circularly brushed, the bezel once again extends the tool spirit and offers a stark contrast with the black of the dial. Beyond its visual appeal, it comes into its own when used together with the rehaut. I shall come back to that.

Restrained, but not austere

The dial wears a deep black. On this understated base, everything is designed for efficient reading.

At twelve sit the propeller logo, the words Zürich 1956 and the name Selectron. At six, one reads P-104 and the water resistance rating, 300 metres. Some might wonder why give a pilot's watch such water resistance, to which Charles Le Menestrel would reply "because we can". Beyond this touch of humour, that water resistance reassures because it demonstrates undeniable robustness. I see it as a very good point.

The indices are painted, except those at twelve, three and nine o'clock, which are applied. At twelve, a cone-shaped index, also applied, points upwards. All are filled with eggshell-coloured Luminova, a discreet shade that warms the overall look without falling into artificial vintage.

The date window, at six, is set in an applied rectangular frame. The disc is white, neither eggshell nor black, and although I am usually attached to tone-on-tone, this departure does not bother me here. One detail I had never come across elsewhere deserves mention: Luminova has been applied around the edge of the date window. The full set of markers thus remains visible in the dark. Here again is a fine demonstration of the brand's eye for detail.

The hour and minute hands are batons with squared tips, an uncommon shape that in no way hinders precise reading of the time. Both brushed, the hour hand carries a band of orange Luminova down its centre. The minute hand is more original, with a chequered pattern alternating painted black and orange Luminova. The seconds hand, arrow-shaped, likewise wears orange and is luminescent at its tip.

All these touches of luminescent material are welcome and logical for a "tool" watch. I did notice, however, that the strength of the Luminova is not uniform. The applied indices glow brightly, while the painted indices and the hands remain more subdued. Uniform intensity would have made the whole thing perfect. That said, in the dark, everything is legible.

The edge of the dial is bordered by a white rehaut with black markings, here too precise and legible. As mentioned earlier, this rehaut is meant to be used together with the bezel, and I shall come back to that, bear with me. In any case, aesthetically, this rehaut brings contrast and visually tightens the dial opening, an effect I like a great deal.

The mechanical brain

The bezel of the P-104 Selectron is not there for decoration. As I mentioned earlier, it carries a logarithmic scale which, paired with the fixed rehaut, turns the watch into a small calculator. The principle is that of the slide rule, the instrument engineers handled before electronics.

This tool was conceived for flight, for pilots calculating heading, speed and distance in mid-air. Its operations hold good for any journey, however. I shall therefore take my examples from the road rather than the skies, because a car speaks to everyone.

The mechanism rests on a simple idea. The fixed rehaut carries a triangle marked KM which serves as the hourly reference for a reading in kilometres. You align a value on the bezel with a value on the rehaut, then read the result opposite that triangle or the known value. The figures are read flexibly, a 12 possibly meaning 12, 120 or 1.2 depending on context, the decimal point being yours to place. With that principle established, three uses follow.

First case, speed. You have covered 70 kilometres in 35 minutes and are looking for your average speed. You set the value 70 on the bezel opposite the value 35 on the rehaut. Without touching anything further, you read the value that appears opposite the KM triangle, namely 120. Your average speed is 120 kilometres per hour. A second marker, placed at the value 36 on the rehaut, allows the same calculation when the time has been measured in seconds rather than minutes.

The next two calculations start from this speed of 120 km/h. The value 12 on the bezel is therefore aligned with the KM marker on the rehaut.

You have 50 kilometres to cover. You want to know the time needed for that distance at 120 km/h. You look for the value 50 on the rotating bezel, your distance, and read the time opposite it on the rehaut. The answer is 25 minutes.

Last case, you are going to drive for 20 minutes, still at 120 km/h, and want to know the distance you will cover. This time you look for the 20 on the rehaut, and read the distance opposite it on the rotating bezel. The result is 40 kilometres covered.

The rehaut does not stop at kilometres. Beside the KM triangle, it carries two other markers, Stat. and Naut. (for statute mile and nautical mile). Keeping my setting at 120 kilometres per hour, I read roughly 75 opposite Stat., that is 75 statute miles per hour, and roughly 66 opposite Naut., that is 66 knots. The same speed is thus expressed in three units, kilometres per hour, miles per hour and knots, in a single operation.

What strikes you is the economy of the gesture. One speed set, and a whole family of answers can be read in a single turn, without pencil or screen. You then understand why these watches accompanied pilots and navigators, at a time when calculating quickly could change everything.

The bezel does not stop at these three uses. Another marker on the rehaut, placed at the value 10, serves as a reference point for multiplications, divisions and unit conversions. Converting miles into kilometres, feet into metres, litres into gallons, all of it is read the same way, by setting a factor and then reading the result.

A proven heart

Beneath the dial beats a Soprod Newton Precision P092, a Swiss automatic movement developed bespoke for the brand. The specifications say the essentials, four hertz, twenty-eight thousand eight hundred vibrations per hour, twenty-three jewels, a forty-four-hour power reserve. There is also a stop seconds and quick date adjustment via the crown, two conveniences one appreciates day to day.

The screwed case back reveals nothing of the mechanics, yet the brand has not given up on care for all that. The rotor has been redesigned in the shape of the OW logo, set on a base engraved Zürich 1956. A hidden attention, in keeping with a watch that would rather work than put on a show.

The reliability of the Soprod Newton Precision P092 movement has been independently tested by the Laboratoire Dubois in La Chaux-de-Fonds, which awarded it Chronofiable certification. The test is no trifling matter, it subjects the movement to accelerated ageing that simulates wear on the wrist, with extreme variations in temperature and humidity, and twenty thousand indirect shocks of varying severity. Only calibres that pass every one of these trials earn the certification.

On accuracy, the P-104 Selectron is rated at plus or minus five seconds a day, regulated in five positions. Over a week on my wrist, I noticed no real gain or loss. That is honest accuracy for everyday life. COSC certification, for its part, is available as an option.

This reliable, well-tested movement stays true to the spirit of the brand.

A real strap monster

The P-104 Selectron comes on a "single pass" nato-type strap, black with an orange stripe that answers the hands.

The buckle and keepers are brushed, the buckle bearing the brand's signature. The construction is well done, without a false note.

This single pass mounting has its virtues. The watch head stays on the wrist even if a spring bar breaks, and the single pass beneath the case avoids raising the watch too much. One reservation, however, and it is purely personal to me. A single pass tends to press a little more on either side of the wrist. Its visual effect is not to my taste. This is not a criticism aimed at the Ollech & Wajs strap, rather an observation I make about all single pass straps.

The standard 20-millimetre lug width throws the field wide open. I have tried plenty of my own straps, two-piece as well as nato, and everything suits it. The dominant steel and the touches of colour on the hands go with a fine variety of shades.

The brand does offer other options, incidentally. You can order a beads-of-rice steel bracelet, which I have had the chance to handle, of very fine quality, its small central links out of the ordinary, brushed and facetted where one usually expects them round and polished. A rubber strap, black or orange, completes the range.

Match confirmed

The pull this brand exerted on me, and this watch in particular, had until now rested on paper alone. A week on the wrist confirmed it.

The P-104 Selectron delivers on its promises. It wears with a comfort its figures did not let on, and it exudes quality, between its steel case, its proven movement and a water resistance that reassures in any circumstance. This is a watch that does not settle for telling the time, simple in appearance, technical the moment you question it. Its legibility is excellent, even if that needs qualifying in the dark, as I noted.

It catches the eye, too. Not through preciousness or showing off, but because it has real presence, the kind that starts conversations between knowing enthusiasts.

To top it all, behind that look lies a genuine heritage, that of a lineage born for flight and calculation.

There remains one thing I really do hold against it, and it does not come from the watch itself: I shall have to give it back.