Yes, it narrows it down to some type of bombers.
The star mark in a circle is a Japanese Army military inscription. So, it might have been Army Air bomber that had an equipment like this... (Strange thing is that Navy also has a record for Toyou company providing a some type of air navigation unit for a plane but not for the Army!)
The number noted on the plate is a serial number. For your reference, I will post this weekend Army bomber instrumentation penel photos for Ki-2, Ki-21, Ki-48, Ki-51, Ki-67 at the Japanese military watch forum but you will note that no such instrument was equipped for these... It must have been a special mission plane or something? All the best.

This gets more interesting all the time. A special mission aircraft or maybe an aircraft that was never built in large numbers and so there is not much data on them. Or maybe it was not standard equipment on any aircraft but test equipment mounted only when requirements called for it. In any case I would think that its operation would be the responsibility of the Bombardier and not the pilot so I would look for photos of Bombardier's stations.

I took it apart but I saw no new clues or stampings on the inside other then the number 49 repeated on some of the major components. I see that the workmanship is top quality with no shorts cuts taken or signs of rushed production. The materials are also top quality and the aluminum case is wastefully thick ,in fact everything about it is over built so I might assume that when this was made there were no major shortages of raw materials and so,with no date to go by, I might also guess it was made in the early years of the war, sound logical ?

All the Best

I decided to look at the Bombardier's station in an American bomber to see if there was anything similar and look what I found . It is called an intervalometer ,in this case installed in a
B-29 to control the cameras. You set it to the time between bomb drops to turn the cameras and and off between the drops. I believe the Japanese timer might be a camera intervalometer. There is also a bomb intervalometer which is used for bomb drops.

Yes, judging from the extra care and a beautiful finish on the bridge and the plate, plus very elaborate entries of the product name, etc., early serial number, I would agree that it must have been made early...Fascinating to hear of your actual observations of the instrument itself, usually you see a clear deterioration of craftsmanship and the quality of materials used for airplane clocks and like... as the war progressed....Thank you for sharing about an intervalometer, one learns new things every day!
For your reference, I have already posted instrumentation panel photos of Army bombers at the Japanese Military Watch forum where I am a member ( and know how to post photos!)
I will see whether I can find some special mission purpose planes...
Regards.

This has been some fascinating group research. A camera intervalometer seems to be the most likely answer.

You might not want to jump to conclusions about whether it would have been for a special mission aircraft or an aircraft not built in large numbers. Not seeing it in a photo of a bombardier's station in a Japanese aircraft doesn't really mean much since there are so few photos of the interiors of Japanese WW II aircraft. I have browsed through about a half dozen different books of WW II aircraft interiors and there are few Japanese photos and what there are seem to be mainly fighter aircraft cockpits. Another thing to consider is that all of the air forces during the war were constantly developing and improving the equipment in their aircraft and refitting whenever something new came along. Aircraft types were not a static thing. All aircraft of a type would not have one standard set of equipment. They would get whatever was available and new when the aircraft was built and then have things added or changed afterwards. The low serial number is enticing to think that perhaps not many were made, but on the other hand Japan did not build many bombers. Their production from 1941 to 1945, by year, was 1461, 2433, 4189, 5100, and 1934. A low serial number does not indicate what the highest serial number was. It would definitely be worth more research to try to find out whether this particular model was built in small or large numbers, but it may be pretty difficult to get much further than where we are now unless someone comes across some more of these to compare serial numbers. It is definitely an interesting object and there are not likely very many around.

Hey Jim!
You are quite right, it is actually very hasty to jump to a conclusion when there are still so many unknown factors...
A couple more info that I researched - Army product identification plates had essentially 3 types, depending on the size of the plates, number of data entered. An Earlier model had 40mm by 22mm or bigger with a product name, sr number, date , one or two army inspection marks, plant name, location, and the war progressed the plate size diminished to 25mm by 12.5mm or smaller.( the middle phase plate and latter phase plate exist)
Also,Anthony has asked me whether Japan had a twin engine fighter model or not...well, they had. J5N code named " Tairan " but unfortunately the cockpit layout is not known.
It is absolutely intriguing to be gathering more info on this mysterious but no doubt precious timepiece!

Now that we know what it is it should be easy to find, a camera intervalometer is a fairly standard piece of equipment on a bomber but as Jim points out ,the photos we need to look
for it are rare . The information we need is rare ,not necessarily the equipment.

It is basically a camera timer with a span delay just like our intervalometers were and I think that it would be useable in many different aircraft just as our could be , not just one model of bomber . Many thousands of these must have been made. Maybe not this exact model but still close enough in looks that we will know it when we see it Someplace out there is a photo of this unit on a aircraft bulkhead and if it is out there, I am sure Naoki will find it.

As far as it being for special mission yes, that is a bit of a big jump to make. But in another sense you might say it was very special since it was the one they did not return from, she was blow apart and crashed in the jungles
of Bougaineville before most of us were born and her aircrew ,they are still out on patrol.

Regarding the early serial number...I don't think that I have explained what I meant quite clearly! It is not so much the smallness of the number but the unconventional way that the serial number is written. ( therefore my tentative impression of the instrument being an early model rather than a later model) Quite extensive Army Air aviation instuments and their product id plantes with their respective serial numbers actually exist ( much to our surprise! I have seen quite a number myself), together with an equally impressive record of companies that provided those parts. Be it an altimer, a turn and bank indicator, etc, their serial numbers, as a rule, followed certain 5-6 digits numbers, plus sometimes combined with 2 alphabets, often denoting a production plant. As the war progressed and worsened for Japan, the data entries seemed to have been simplified, unified and less elaborate. No alphabet entries found from 1942 for the Army Air serial numbers, just 5-6 digits numbers only.
I have never seen a 2 digits serial number for any of the surviving Army air instruments. ( not for Navy Air either...) It is so odd that very early id plate has only 2 digits entry. On top of it all, this particular company that made the instument is not listed in the extensive Army list amongst the companies that made other parts...

I see your logic now, it does not follow the expected numbering rules so maybe it was an early test model or something built especially for some use ,Yes that is very odd then. It would certainly account for the care taken in its construction as well.

I have been looking for interior photos myself (and learning a lot about Japanese Aircraft at the same time) the past few days and have found at least a dozen of all makes and may have found something in a copyrighted and blurry photo of the navigators station of a Mitsubishi G4M3. On the port bulkhead below what might be a bombing computer is a box that looks to be the dimensions of this one but unfortunately the photo is so poor that I cannot make out enough detail but you might have better shots. I also came across this Mitsubishi plate which might interest you for your files. Best Regards

Boy! It just does't get any better than this. The only reason I interrupted the thread is so I can have instant notification of additional posts. Thanks so much, Phil.

Hello Phillip, help us here! More input, the better!
Anthony, you have been really busy as well...Interesting to hear of G4M3 photo, G4M3 was, as you probably know Navy type 1 attack bomber. ( as well as being a student of horology, I have been a Japanese military model plane enthusiast as you can tell!) Well, I have checked the cockpit layout and the instrument panel but the camera intervalometer wasn't listed in a standard equipment list.( of course, that doesn't mean it wasn't there...but to say that at least it wasn't a normal practice) Besides, your instrument has a clear Army seal (I will come back to it later ), therefore I would have thought that it would be more lilely to be installed in a plane like Army heavy bomber Ki-49.

I verified Army air instument serial numbers ( which are somehow different from Navy's!!) for altimeters, air speed indicators, magnetic compasses. They are, as a rule, never strict production serial numbers as such but rather cryptic but logically placed numbers, denoting a company that made it (usually prefix but not always ) and the actual inspection number regardless of types. It is very complex to decipher totally accurately but they all follow certain rules. When some part was subcontracted to other company, they were given a different number! They were actually quite meticulous about who made what.
I will come back to an issue of the military seal some other time.
Best Regards.

Hi Folks,
Could this instrument have come from a torpedo bomber? They may have needed cameras to check whether the prop was running before launching it, if a dud motor on board, they could cancel the drop and get out pdq! ????
I'm no expert here at all, just 'thinking aloud'
Best regards
John Woolsey

Naoki, It would appear that Japan was also fond of using such codes and sub codes to identify the makers of rifles and bayonets. In publications for arms collectors I have seen the various manufacturers codes explored and explained in great detail.

John, I was also wondering why such a camera would be required in a bomber. Some WWII fighters had cameras attached to the machineguns. The film was developed and played to see what the pilot had been shooting at and to award credit for a kill. These films are available in WWII archives.

Best regards,
Greg

Hi Greg,
Gun cameras in fighters were generally mounted in the gun bays along with the film and actuated when the guns were fired, certainly stopped all the ludicrously high 'kill' rates claimed by some pilots.

Another thought for the timer, could it have been used for timing the photo flash drop after a bomb drop?
Time delayed flares were usually released to illuminate a drop zone and photographed to determine how close the bombardier got to the the aiming point, this was the case in the RAF, but not sure about the USAF or other nation's Airforces.
Could it even have been for timing the run up to a drop zone, perhaps with an automatic bomb release via the pre-set timer?

just some thoughts!
Best regards
John

Hey Greg!
You are absolutely spot on...If I may take a rabbit trail about military markings...you will never know where a clue is hidden for understanding serial numbers and markings regarding Japanese military watches, clocks, etc... Sometime ago, you shared with me your own theory of the use of the cherry blossom marking on a Seikosha military wrist watch ( the actual meaning of it baffled Japanese collectors, to say the least!) you thought that " sakura " marking could have been used interchangeably both by Army and Navy...(a very radical thought, considering their rather independent existence and the intense rivalry between them) Well...have a look at the product id plate for the Navy's famed Zero type 22 fighter plane by Mitsubishi that Anthony has kindly provided right above. You will be surprised!!

The second line from the bottom shows 3 markings, including a cherry blossom military mark(!!!), together with a Mitsubishi company mark, military inspection mark.

The fourth line from the top is a serial number which is actually an inspection number, with a company prefix( not always the same...sometimes a suffix! Help!), yet again providing a sample of their general practice of identifying a production company and an inspection number combined together, often totalling up to 5 to 6 digits.

John, I also tend to think that Japanese Army Air's use of the bomb timer camera was same as that of RAF.
Regards.

Naoki,

Thank you for your observations. For the benefit of our readers, the Sakura (cherry blossom) is a significant and ubiquitous Japanese cultural image. Not well understood outside of Japan. In the military context, it is symbolically linked to the bushido (warrior spirit) of the Samurai. The image appears upon Army and Navy insignia, swords, and so forth. At one point, I confused the Sakura with the Chrysanthemum mark found on Japanese rifle receivers, however, the Chrysanthemum is the mark of the Emperor, the Sakura is something different.

Thus, it may be possible that the military forces of Japan settled upon the Sakura (cherry blossom) as a combined Army/Navy code, like the AN stock number codes of the U.S. Army/Navy air forces in WWII

Now that you mention the Sakura mark on the aircraft i.d. plate, the third marking to the right of the Sakura on the i.d. plate, is also interesting. This letter in a circle looks like the same inspection marking found inside the cases of Seikosha pocket chronographs. All of the watches I have seen with this mark have also had an anchor stamped next to it.

Best regards,
Greg

Hello All Hope you had a Happy 4th, let me catch up here,

The Cherry Blossom it seems was used by the Japanese minister of defense as well integrated into the designs of the flags of the various Ground ,Maritime and Air Self-Defense Forces of Japan.

The cherry blossom is a metaphor for the life and death of the warrior ,youth too soon sacrificed . The cherry blossom falls at the height of its beauty and the warrior at the prime of his strength and youth. Anyone who was in the military remembers how we thought 32 was old.

As far as why use a bomb camera , to record what the bombs hit. If you wish to film bombs hitting a target and lets say you know in advance based on your altitude and other factors that they will hit the ground 20 seconds from release. You set the camera timer to start counting down 20 seconds from the time the bombs are released and at the end of that 20 seconds it starts the cameras. The camera might have to be angled a bit aft .

I was wondering if the makers were interested in the aerodynamics of the drop when Naoki said it was a "inspection camera" ,I know that was an issue with new bombs, how they would act in
as they hit the airstream but the more I though along those lines the more unlikely it seemed and then I found the same kinds of timers used in US Bombers for bomb drops and Cameras and that clinched it


As far as checking for a dud before release ,no, that would not be possible since these were film cameras,not real time and also a torpedoes prop was not powered until it dropped from the cradle and a pin yanked out in the fall .

Wing gun cameras were wired into the firing circuit to start and stop with the firing of the cannons. They were used not only to record hits but to record what damage was being done as well as to see the tactics of the opposing pilot in a dog fight.

With Japanese pilots late in WW2 for example it was noticed that there was a very standard maneuver taught to the new pilots to break away from a perusing American aircraft starting with I think a break right and then not an expected dive for speed but a climb which Zeros were very good at,once this trick was learned by American pilots it became deadly to use it.

Hello Anthony,

Your intervalometer was used in a “Model II” bomb (strike, inspection, or observation) camera built for the Japanese Army Air Force (JAAF) in early WWII.

The complete outfit included the intervalometer, camera, power cords, and a control switch (looks like a gun trigger). I wrote an article on a complete outfit made by Nippon Kogaku in the March 31, 2005 (NHS-87) issue of the Nikon Journal. A back issue containing the article can be obtained from the Nikon Historical Society at http://www.nikonhs.org/
The issue index is at http://www.nikonhs.org/NHSindex92.PDF

The control box and trigger switch in my outfit were made by a different manufacture that yours (Fuji Koku). The camera depicted in my photo was made by Nippon Kogaku (today’s Nikon corp). These units were used in conjunction with the JAAF Type 88 bombsight. The trigger switch has a leather strap that can by attached to the main tube of the Type 88.

The trigger mechanism is also a interesting timing device. When you press the trigger, the timing mechanism runs for several seconds completing a circuit. One of the images below shows a closeup of the timing mechanism.

A 1946 U.S. Air Technical Intelligence Review titled “Japanese Photo Intelligence Equipment in WWII”, describes this unit as a “Bomb Strike Camera”. The study has a photograph of two complete units but does not have any detailed information about the camera. The study indicates that three cameras were shipped from Japan to Wright Field Ohio in Dec 1945.

Rich

Sorry it took so long to answer,this got buried and I missed it. Some kind of a camera intervalometer had been my best guess but I see now the whole system. Since yours is Fiji and the one in the Photo is Nippon Kogaku they clearly had several different contractors making these which also means that it might have been a more common a piece of equipment then it would seem,but mystery solved now,Thanks!