question, in US SUB they use UZO?

[Eric75]

Or something similar?

Thanks

[Seeadler]

It's called TBT
http://www.bowfin.org/website/education_program/education_frameset.html

[AirborneTD]

The fleet boats had 2 mounted. 1 forward and one aft on the sail.

[Eric75]

great!Thanks for response

[mookiemookie]

It's called TBT
http://www.bowfin.org/website/education_program/education_frameset.html

Here's a corrected link for this: http://www.bowfin.org/website/bowfin/bowfin_systems/TBT/tbt.htm

[Threadfin]

Good link with more info on the system.

http://www.maritime.org/fleetsub/elect/chap14.htm

[The WosMan]

I am not sure if the optics on the TBT were better than the german UZO but I do know that it was built much better that the UZO and did not require disassembly for dive. The germans had to take the UZO down every time they went to dive. The TBT was able to withstand the pressures of the dive. I think it was also capable to transmitting marks and bearing to target to the to the TDC electrically.

[Sailor Steve]

I've been running into some confusion on this myself. I just finished reading Peter Padfield's War Beneath The Sea, and he indicates that the TBT as shown in the manuals and the Bowfin site might actually be post-war developments (as shown by the Bowfin's 1946 date on the document). Padfield seems to think that the first TBTs were used in 1943, and were similar to the German UZO with a regular set of binoculars slotting into the transmitter station, and thus not waterproof.

I've always previously believed in the completely waterproof US device, probably spoiled by SH1. I'd be interested if anyone can come up with more detailed information, as currently I'm at a loss which to believe.

[cmdrk]

O'Kane mentions in his books of using the good old 7x50's clamped on the bearing transmitter. The 7x50 was the standard binocular at the time - I believe.

[Capt. D]

I've been running into some confusion on this myself. I just finished reading Peter Padfield's War Beneath The Sea, and he indicates that the TBT as shown in the manuals and the Bowfin site might actually be post-war developments (as shown by the Bowfin's 1946 date on the document). Padfield seems to think that the first TBTs were used in 1943, and were similar to the German UZO with a regular set of binoculars slotting into the transmitter station, and thus not waterproof.

I've always previously believed in the completely waterproof US device, probably spoiled by SH1. I'd be interested if anyone can come up with more detailed information, as currently I'm at a loss which to believe.

Take a look at the sites that Mookiemookie and Threadfin gave. The pictures and discription I think will cover what you are talking about. The TBT has a built in binocular of the high light transmission type (?) but the picture also shows a spot for binoculars to attach. I think one used one in conjunction with the other. The one that you attached assisted you in f"inding" a target and the one that was permently attached was used to "target" the target (having cross hairs) and then transmitting the information to the TDC.

Hope that helped.

Happy Hunting:ping:

[Sailor Steve]

No, it doesn't help. As I already said, both of the references given at those sites are dated 1946 - AFTER the war.

On the other hand, cmdrk's reference to O'Kane's book is a start.

[Threadfin]

I think you're right Steve, that's my recollection as well. I provided that link more as an overview of how the system worked, and how it was linked from bridge to control room/TDC. But I definitely have the same impression as you, that it was more likely the skipper stuck his binocs on the mounts as the need arose, then went below with them upon diving.

[Crosseye76]

There are several good sources showing the TBT mounts and even a few that show them mounted. The Mare Island pics are very valuable, it seems they photographed EVERYTHING during overhauls. The TBT units in the pictures match the ones in the links in the other posts in the thread. (1)

Most of the pictures show the Late war boats, with everything cut down and 2 TBT's mounted. One is forward, on the bridge, and the second is aft on a stand alone pedestal between the 40mm / 20mm mount and the SD radar mast.

One very interesting set of photos however, shows the USS Bashaw's conning tower. She is alongside a tender is Brisbane in August of 1944. She has her 2 TBT mounts in box sponsons on either side of the Bridge, not fore and aft. (2)

The reason for the Bino mount on the TBT was (IIRC) the TBT had pressure proof optics, but they were not the highest quality, and as they were constantly exposed, they got fairly grungy. Also (again IIRC) they had little or no magnification.


Sources:

1. U.S. Submarines through 1945. Norman Friedman, Naval institute press. PP 219, 235, 236.

2. U.S. Subs in action. Robert C. Stern, Squadron / signal publications. PP 40 and 41.

[Gino]

Two pictures of the fixed mounted TBTs on board of USS Cod

http://img177.imageshack.us/img177/7897/img0072ln1.th.jpg (http://img177.imageshack.us/my.php?image=img0072ln1.jpg)

http://img177.imageshack.us/img177/5637/img0071rx9.th.jpg (http://img177.imageshack.us/my.php?image=img0071rx9.jpg)

The TBT's are just what they are: Target BEARING Transmitters. Only the bearing is fed into the TDC. Range had to be obtained differently.

groetjes,

[OneTinSoldier]

Good pics Gino, thank you. By the looks of them I'd say they were pretty much permanently affixed and not removed every time the sub submerged.

[Elder-Pirate]

Am trying to find answer to sailor Steve's "1946" question when I stumbled upon this about "WWII Sub Periscopes". May be old news to some of you but as I was a DD Sailor a lot was unknown to me about Subs.

http://www.maritime.org/scopes.htm


Another link on the WWII Sub and all of its parts.

http://www.maritime.org/fleetsub/index.htm


EDIT: Sailor Steve, from other links I've seen ( also above links ) this date is the date the articles were printed, Not when parts used. Copyed from maritime.org: From: Submarine Electrical Installations, NAVPERS 16162, June 1946

[Crosseye76]

And here's a great shot of the TBT, like the one on the Cod, in place on a wartime Fleet boat.

It'a a Mare Island shot of the USS Trigger taken during an August 1944 refit.



http://www.navsource.org/archives/08/0823708.jpg



And the USS Baya, in the South China sea, Spring 1945.


http://www.ussbaya.com/image24.html



.

[Sailor Steve]

Two pictures of the fixed mounted TBTs on board of USS Cod

http://img177.imageshack.us/img177/7897/img0072ln1.th.jpg (http://img177.imageshack.us/my.php?image=img0072ln1.jpg)

http://img177.imageshack.us/img177/5637/img0071rx9.th.jpg (http://img177.imageshack.us/my.php?image=img0071rx9.jpg)

The TBT's are just what they are: Target BEARING Transmitters. Only the bearing is fed into the TDC. Range had to be obtained differently.

groetjes,
But those are both modern-day pictures. The equipment could have been installed at any time. Those might not even be that particular sub's originals.

No help at all.

Crosseye76, your first link doesn't show up. The second one looks more like binoculars fitted into the control arm than the waterproof ones shown by Gino. Again, it looks like the waterproof TBT was a later development.

[Crosseye76]

Look at that second picture closer. Look close at the size of the optic unit shown in that picture and the second picture Gino posted, look at how much room the optic unit takes up in the TBT frame, both horizontal and vertical. The size of the Optic unit in both photos compared to the Selsyn base. They are the same sized unit.


Look at the binos the Skipper of the Baya is holding. They are quite a bit smaller than the TBT optic unit.


Here is another link to the Trigger TBT pic.

http://www.navsource.org/archives/08/08237.htm


These, and the Hardcover book links I posted earlier show the 1943 -1945 TBT matches the equipment on the Cod.

It's very possible the first TBT was a non-waterproof mount for a regular set of binos. The photo records do not show it clearly enough on the early war boats to be sure.

[Sailor Steve]

Thanks, Crosseye76. That bridge shot of Trigger does help. If the August 1944 date is correct (and there's no reason to believe it isn't) then they had the fully waterproof permanent TBT by that time. O'Kane indicates that he had the 'dismountable' kind in 1943, so they may easily have come up in that time frame, considering all the other advancements they made.

Now for the kicker: is Padfield correct? Did they have anything at all in 1942, or was it a later development? As I said, SH1 had them right from the start, and with x1, x2, x4 and x8 magnifiers. I just took it on faith that they got it right, and now I really want to know.:hmm:

[Elder-Pirate]

Ok this was kind of hard on the ole eyes but is this what your looking for ? And note the date of this photo is August 1944.



http://i4.photobucket.com/albums/y116/oleman/TriggerTBT.jpg

This close up of the bridge of the Trigger (SS-237), was taken in August 1944 during refit at Mare Island. Details of the compass repeater target bearing transmitter and alarm switches are seen behind the protective venturi shield. The hatch leading to the conning tower is at right on the deck. The pole in the center of the photo is the mast for the "SJ" antenna. This shot was taken from the port lookout platform.


EDIT: crosseye76, you beat me to it. LOL

[Crosseye76]

I was wondering the same thing Sailor. I've been looking at pre-war and early war pics of Fleet boats. All the Mare Island pics of the early boats, with the big, non-cut down Bridges don't really show the TBT. It does not seem they had the one mounted aft until they started cutting down the bridges in 1943.


There a great pic of USS Seal that shows the aft mount in March 1943 (Love Mare Island pics ! ), but the frame and optic unit is not mounted. Ditto for one of Wahoo in about July of 1943. :cry:

However, since pre-war U.S. sub doctrine called for submerged, sonar attacks, I'd be surprised to see a fully waterproof TBT on early war boats, and I have no doubt the first units bore almost no relation to what the later ones looked like.

The pace of change was frantic in electronics, as any comparison between early war masts and the late war forrest of Periscopes, SD and SJ radar, radio and ESM fits shows. I'm sure that applies to items like the TBT as well.

[Torpex752]

Good Thread!

TBT as we see it is a late war development.

S-Boats through Gato's did not have any device that actually fed into the TDC. (The S-Girls didnt even have a TDC so I am curious what they (The dev team) did with that) Early in the war it became obvious that the need to have a simple device other than the periscope (periscope visibility issues) to give accurate bearings in order to give proper gyro setting information into the torpedo's for surfaced approach tactis. Remember the pre war doctrine was to approach and attack submerged so there was no developed device for surfaced attacks. Early versions were as simple as a water tight sealed shaft that penetrated into the sub with a set of sights mounted on top and the OOD lined the target in the sights ( like a rifle). Inside there was a needle attached to the rod, and a stationary ring with the ships relative bearings on it. The Officer running the tracking plot would have the sailor (the same sailor who called the periscope bearings when submerged) call out the bearings and the TDc operator would adjust the variables (speed, range, AOB) to match up, ultimately tweaking the solution enough to get a final solution.

I dont know the exact date but there were alot of variables in this area of WWII sub equipment. Much like the mechanism that rotated the early radar.....The guys gut tired of rotating it manually (thats right with a wheel!), and the A-gangers took washing machine motors when they were in port and rigged them up to rotate the radars! LOL

Frank
:cool:

[-Pv-]

A gripping read, the war partols of the USS Gunnel do not mention the TBT until third patrol 1943. An AMAZING 8 patrols for this boat. The 2nd patrol is a heart pounder.
-Pv-

[Sailor Steve]

Thanks for that, Torpex752. The more we can find out about this the better, at least to my mind.

Washing machine motors, indeed. Stupid Yankee ingenuity.:rotfl:

[T&L5]

I realize this thresd is kind of old, but ...
I believe early on during the war there was a set of brackets on the bridge (fore and aft) which the OOD/Cap'n's binoc's would be clipped to.
Later on in the was these were upgraded to the waterproof TBT's.

[Rockin Robbins]

I have found evidence that the uzo was extensively used on certain American boats in a completely distinct manner than the TBT! This uzo was used on only a few American boats with crews comprised of expatriate Greeks. Some of them were from the island of Lesbos where the uzo was in wide use and brought it with them to America. When they were subsequently assigned to American submarines, the opportunity presented itself and the uzo found wide use on two American subs, Darter and Bullhead. Knowing that this is an amazing find that might be doubted among subsimmers, I have found a photo of the uzo and paste it below:know:
http://i196.photobucket.com/albums/aa293/RockinRobbins13/Ouzo_Bottle.jpg (http://i196.photobucket.com/albums/aa293/RockinRobbins13/Ouzo_Bottle.jpg)

Oh.....that's the wrong......spelling? How could Google be wrong?
Never mind!

[Elder-Pirate]

http://i4.photobucket.com/albums/y116/oleman/giggle1-1.gif

[Sailor Steve]

There's one in every crowd. Sheesh!:nope:









Usually it's me.:rotfl:

[joea]

I have found evidence that the uzo was extensively used on certain American boats in a completely distinct manner than the TBT! This uzo was used on only a few American boats with crews comprised of expatriate Greeks. Some of them were from the island of Lesbos where the uzo was in wide use and brought it with them to America. When they were subsequently assigned to American submarines, the opportunity presented itself and the uzo found wide use on two American subs, Darter and Bullhead. Knowing that this is an amazing find that might be doubted among subsimmers, I have found a photo of the uzo and paste it below:know:


Oh.....that's the wrong......spelling? How could Google be wrong?
Never mind!

Actually they forgot the pa- it's opa-uzo. Only problem is aiming accuracy drops the less liquid there is inside. :rotfl:

[Roger Dodger]

Target Bearing Transmitter
USS Bowfin (SS-287)
TBT
http://www.bowfin.org/website/images/grey_dot.gif The target designation system is used for the purpose of transmitting and indicating the bearing of the target from the bridge or radar to the torpedo data computer (TDC) and the two plotting stations. It is a simple selsyn-operated system using manually operated bearing transmitters on the bridge and an automatic transmitter coupled to the train mechanism of the radar.

Target Bearing Transmitter: This instrument consists of 2 permanently mounted peloruses on the bridge. One is located at each end of the bridge. Each pelorus has a pair of watertight and pressure-proof binoculars of the high light transmission type. An illuminating system is built into them to make the cross wires visible when the instrument is used at night. The pelorus can be rotated through 360 degrees in azimuth and is equipped with a scale so that the operator may read the bearing at which the instrument is set. A selsyn generator inside the pressure-proof case of the instrument transmits the bearing of the target when the pelorus is pointed at it. The hand contactor for the buzzer system is built into one of the training handles.
Source: http://www.bowfin.org/website/bowfin/bowfin_systems/TBT/tbt.htm

http://i204.photobucket.com/albums/bb239/RogerDodger1946/tbt.jpg

[DeepSix]

That blurb from the Bowfin site is a quote from Fleet Type. More images of the TBT and other targeting equipment here:
http://www.maritime.org/fleetsub/elect/chap14.htm#fig14-08.

Even though Fleet Type was published after the war, it was so soon after that it represented the very latest developments that came directly from wartime experience.

Steve, my guess (and I stress "guess") would be that the TBT as you're asking about it was developed sometime during the war - like '43 or '44 as Padfield suggests, since that's the time frame when other problems (torpedos, exploders, tactics, etc.) were worked out and when the submarine service in general seems to have coalesced around definitive skills, tools, strategy.... But again, pure guesswork on my part.

FWIW, Blair does not mention the TBT at all until describing one of Trigger's exploits on January 31, 1944. He describes it simply as "a pair of binoculars in a swinging mount designed especially for night surface attacks" (Silent Running). Not even Friedman mentions it but once - 1945 refits of several boats at Mare Island - in a book I thought had every detail on fleet subs, no matter how seemingly minute (U.S. Submarines Through 1945). Yet neither Blair nor Friedman says comments about it as an invention....

Time to do a little more close reading; I'd like to know the answer to this question as well!

[Edit - seems like Calvert says something about taking binocs on and off the bridge with him to go stand watch, but no mention of a waterproof TBT. Will have to check.]

[seaniam81]

Richard O'Kane makes reference to the TBT

TBT. Target bearing transmitter, one forward once aft on the bridge; receives binoculars for transmission of bearings to the conning tower.

[seaniam81]

Richard O'Kane makes reference to the TBT

TBT. Target bearing transmitter, one forward once aft on the bridge; receives binoculars for transmission of bearings to the conning tower.

The key word here is receives, meaning you placed the binoculars into slot and hit a button and the bearing would transimit down to a repeater in the conning tower.

O'Kane on page 12 of Clear the Bridge acutally disgribes a TBT

The V-shaped receptacle of the TBT would take the center hinge pin of a pair of binoculars to transmit bearings...

Hope this helps.

[Sailor Steve]

Richard O'Kane makes reference to the TBT

TBT. Target bearing transmitter, one forward once aft on the bridge; receives binoculars for transmission of bearings to the conning tower.

The key word here is receives, meaning you placed the binoculars into slot and hit a button and the bearing would transimit down to a repeater in the conning tower.

O'Kane on page 12 of Clear the Bridge acutally disgribes a TBT

The V-shaped receptacle of the TBT would take the center hinge pin of a pair of binoculars to transmit bearings...

Hope this helps.
Again, none of this is new information. The question is WHEN did the fully-fledged TBT come into use? And what where they using in 1942?

[Munchausen]

And what where they using in 1942?

As late as January 1944, the Jack was still without any TBT at all ... using only a basic pelorus.

I also worried about Dykers being on the bridge with no TDC or plot to help him get the picture. He was used to standing about three feet from the TDC, where he could easily see, continuously updated, the target's range and bearing, course and speed--everything he needed to know, there at a glance. Up on the bridge, he had nothing on the tactical picture other than what he could visualize in his head.

... One of the key things in shooting torpedoes was to get the exact bearing of the target set in the TDC just before you shoot. With the periscope three feet away from the TDC in a daytime periscope attack, this was no problem. At night it was a different matter. Someone had to look over the gyro repeater on the bridge with a thing called a pelorus and while looking at the target read the bearing from the illuminated dial underneath. Freddy Laing had been assigned this job.

"Jim, as soon as you get the bearing from us, shoot the first three. We'll give you a new bearing on the second target for the next three."

"Aye aye, sir."

"Bearing two four," from Laing.

"Fire one!" I said as our first surface-fired torpedo lurched from the bow of the submarine.

"Fire two!...Fire three!" The next two went out at eight-second intervals.

"First three are gone," I reported to Dykers.

"Here's the second ship--bearing one three," from Laing.

"Fire four!...Fire five!...Fire six!" The last three went out as scheduled.

... "How come you gave us a bearing on a ship in the far column for the second salvo? I thought we were going to take two of the tankers in the close column," I asked. "I know we had their course and speed nailed right to the mast."

"My fault," said Laing. "In the excitement I gave you the bearing on one of the ships in the far column. We were so close I got them mixed up."

-- from "Silent Running," Chapter 7, by James F. Calvert

[DeepSix]

I apologize for the lengthy quote....

Perhaps the most serious deficiency, and one to be coped with immediately, was the lack of a proper instrument for taking target bearings from the bridge at night.

The torpedo directors designed for surface ships were not adaptable for submarine use. In 1941 the Bureau of Ships designed for submarines a dummy pelorus, and this was in the process of manufacture when war broke out.

Serviceable for daylight action, this dummy pelorus was practically useless for nocturnal warfare. Few submarine skippers would risk fracturing a surface blackout with a flashlight, yet the dummy pelorus could not be read by braille, and its reading necessitated a light on the bridge. The urgent need, therefore, was for an unlighted instrument capable of transmitting bearings from the bridge to the fire control party in the conning tower. This need was met by the "Mare Island" type target bearing transmitter (T.B.T.).

A somewhat makeshift affair, this T.B.T. was designed and produced by submarine personnel working in cooperation with Mare Island Navy Yard technicians. It served a dual purpose in permitting the operator to take bearings in a blackout and in transmitting those bearings to the fire control party below. Despite impromptu construction, the Mare Island T.B.T. filled the bill, and it did yeoman service on U.S. submarines throughout the early part of the war. At the war's outbreak, however, no more than a few of these instruments had been installed. Most of the S-boats were equipped with the "night blind" dummy pelorus. Only a small minority of the fleet submarines had the Mare Island T.B.T., or a "reasonable facsimile" thereof - some local adaptation of the device.

At any rate, at the start of the Pacific War, torpedo fire control was in a formative stage of development and so were the tactics of night warfare. For night firing on the surface, experienced submarine officers recommended that the periscope angle computed for a straight bow shot be set as a gyro angle on the torpedoes, and the order to fire be given as the point of aim passed the jackstaff.

- from United States Submarine Operations in World War II (Roscoe), p. 57.

[Sniper297]

I think most people here have read RUN SILENT, RUN DEEP by Edward L. Beach, that was actually the first of a trilogy, the following books being DUST ON THE SEA and COLD IS THE SEA. In the second book, DUST ON THE SEA, he describes replacing the old TBT clamps for standard binoculars on the EEL with the newer style TBT, and further describes altering the bridge to remount the TBTs in bulges on the sides rather than fore and aft. The EEL also got two 5 inch guns, one each fore and aft of the conning tower. Refit was 1943, after coming back from the patrol in RUN SILENT, RUN DEEP where he killed Bungo Pete.

Funny aside here on the washing machine motors - I had an Uncle who was in WWII over in England, someone was showing him a Brit radar in '44. The guy had a standard doorbell pushbutton mounted next to the PPI scope, and whenever he pushed the button the sweep reversed rotation. Later he took Uncle Bob out to show him the radar dish itself, mounted on a round hut roof. Inside the hut the radar mast was connected to a pole, which was connected to a tandem bicycle with two RAF enlisted men pedaling it around in circles to rotate the dish. The pushbutton did indeed ring a doorbell inside the hut, and whenever the poor buggers heard the bell they had to stop and pedal in reverse. :ping:

[Sailor Steve]

DeepSix and Sniper297, those are great sources! I have Roscoe, but it's buried deep in my rental storage unit and I can't get anywhere near it. So early war boats couldn't see in the dark, and periscopes are useless, so we need to enter all TBT information by hand, by guess and by golly? Sounds like fun!

I have an interesting, but not funny aside: USS Nerka, the fictional boat from Run Silent, Run Deep, was actually a real name assigned to a Tench class sub that was cancelled when the war ended, and never built.

[cmdrk]

Slightly off topic,

I stumbled upon a pair of 7x50's in its storage case. Stamped on it is a reference to BurOrd Navy - Mark 30 Mod 0 - 1944 - Made in New York state (I believe).

The mirrors in it are still aligned, the lenses are not coated (probably the norm for the time), but they are unhazed. They're priced $99 US. It's not financially prudent for me to buy them right now. I just had to replace my crapped out monitor. But it's neat to think they may have been used on a sub. A piece of history and usefull.

[DeepSix]

So early war boats couldn't see in the dark, and periscopes are useless, so we need to enter all TBT information by hand, by guess and by golly? Sounds like fun!

Seriously! Wouldn't you like to meet the salt who came up with "fire when the jackstaff passes the point of aim"?? ("Now would be a good time to shoot, sir, if you please...."):D

The pushbutton did indeed ring a doorbell inside the hut, and whenever the poor buggers heard the bell they had to stop and pedal in reverse. :ping:

:rotfl:

@cmdrk - thought you might find this interesting: http://fantao.home.att.net/mark30.htm - not a whole lot of info but might get you started; I do know that the Mark 91 and I think the Mark 93 (both by Bausch & Lomb) were used on subs.

[cmdrk]

Thanks DeepSix,
That's the one. Spencer Lens. Don't see any difference from Mod 0 & 1, going by the pictures.

[DeepSix]

Yeah, they look identical to me, and I don't know enough about them to have any ideas on the distinction. I bet, though, that there are some optics hobbyists somewhere on the web.

Looks like, depending on condition, that pair might be worth more than $100. I saw an eBay ad for a pair that was going for around $1000 - but it may have been a different model. Anyway, they might be a good bargain.

Cheers,
Rob