TDC vs Position Keeper discussion

[AVGWarhawk]

CONFIDENTIALSLM 1 204. RANGE - MARK: A phrase which when used by the Approach Officer during a periscope observation directs the Periscope Assistant to read the stadimeter or telemeter range and informs the Fire Control Party of the time of the range. When spoken by the Radar Operator it indicates that the radar is on the target and the range repeaters are reading correctly. It is usually paralleled by a buzzer and a mark light in the latter case.



I believe this demonstrates that the TBT/scope were not connected to the TDC. It was all done via voice and visual readings.


The rest of this found below and a great read:


http://hnsa.org/doc/attack/

[heartc]

AVGWarhawk, you quoted what "RANGE - MARK" meant. We talk about "BEARING - MARK" though. Also, as I said above, I'm positive that at least the TBT was connected. Heck, maybe not to the TDC directly, maybe there was a readout next to it on the conn and Joe sailor entered it into the TDC, but this is not the point, the point is that bearing was TRANSMITTED INDIVIDUALLY. And in case of the TBT via a button (because the thing was on the bridge while the TDC was below). Check the quote I provided above.
With the periscope I think there was a readout on the gizzmo itself which could be read by a bystander when the CO/XO said BEARING - MARK. I could digg it up as well, but it would be pointless - since the point is that BEARING was a seperate and independent entry into the TDC, no matter how that entry was exactly done in the end.

[heartc]

I see it coming how I will have to take a DosBox avi vid out of SHI's TDC, since this was done 100% right. What hampered the usefullness somewhat was the graphical representation of the world, with ships being 2D and visibly changed their AOB only in 15-20 degree steps, so you had to refer to the bird's eye map view to judge the angles more often than not.

[AVGWarhawk]

Originally Posted by heartc

AVGWarhawk, you quoted what "RANGE - MARK" meant. We talk about "BEARING - MARK" though. Also, as I said above, I'm positive that at least the TBT was connected. Heck, maybe not to the TDC directly, maybe there was a readout next to it on the conn and Joe sailor entered it into the TDC, but this is not the point, the point is that bearing was TRANSMITTED INDIVIDUALLY. And in case of the TBT via a button (because the thing was on the bridge while the TDC was below). Check the quote I provided above.
With the periscope I think there was a readout on the gizzmo itself which could be read by a bystander when the CO/XO said BEARING - MARK. I could digg it up as well, but it would be pointless - since the point is that BEARING was a seperate and independent entry into the TDC, no matter how that entry was exactly done in the end.

Read the link I have above this post. It lays out everything. Includes how the solution was obtained via voice and visual. No mention of a connection of the TBT/Scope to the TDC or PK. In fact, it shows that two men ran the TDC and PK. Please read it, it is very good.

[AVGWarhawk]

Originally Posted by heartc

I see it coming how I will have to take a DosBox avi vid out of SHI's TDC, since this was done 100% right. What hampered the usefullness somewhat was the graphical representation of the world, with ships being 2D and visibly changed their AOB only in 15-20 degree steps, so you had to refer to the bird's eye map view to judge the angles more often than not.

I don't think using SH1 TDC is concrete evidence. Remember, some functions are added to help us(lock scope/TBT) because we are only one person. When I get the time I will dig some more and attempt to obtain concrete evidence. I do not doubt what you have seen/read but I have seen the contrary that these two instruments were only connected via voice and sight of person using them.

[heartc]

I will repeat my quote from above:

"Hours passed. Finally I could make out a faint place on the horizon where the haze was a little darker. "Conn - bridge. Enemy in sight. Stand by for a TBT bearing!"
I jammed my binoculars into the TBT, centered on the smudge, pressed the button. The skipper's rasping voice came back: "That's him. How many can you see?""

Beach didn't say a word about the bearing. He pressed the button. I don't think he makes this up.

And this confirms it:

http://www.bowfin.org/website/bowfin...ms/TBT/tbt.htm

Note the "On Bearing Contact Marker" in the picture.

Also check this:

http://www.fleetsubmarine.com/tdc.html

"The TDC was also linked to the boat's active sonar, integrating target range and bearing readings from that source. As radar became available, it was also linked to the TDC."

I would say it is pretty clear now.

[AVGWarhawk]

Excellent finds! Confirmed as well. Now, what do you think we need in SH4 to have this work. What type of workaround because I do not think we will be seeing any patch for this.

[heartc]

Well, as I said, I hope that bearing is also transmitted by just "sending" speed again via the upper right hand dial, cause this would most closely simulate the mark button, given that target speed stayed the same.

"Sending" a range measurement to enter bearing definitely works, but it's a bit arkward since it takes excessive time for what should be a "one click" job. Someone suggested that range is in fact the only data that will also transmit bearing. I'm not sure about that and didn't test it recently.

[AVGWarhawk]

The set up is a bit cumbersome for sending data. But, once I have a good read with my PK and tracking looks dead on, that's pretty much it. Drop the scope and watch the PK for the actual firing of the torps. Whatever the case, I believe we are stuck making due with what we have.

[heartc]

Yep, it's not anything like a showstopper. In fact, sending bearing via speed transmission would be good enough, maybe they can incooperate that if it is not yet the case. Sending bearing via range transmission is ok, too, it just makes it a bit cumbersome when you want to aim at specific parts of the target with the crosshairs instead of tuning the spread settings, or simply wish to renew the bearing the moment before firing.

[Snowman999]

Originally Posted by heartc

AVGWarhawk, you quoted what "RANGE - MARK" meant. We talk about "BEARING - MARK" though. Also, as I said above, I'm positive that at least the TBT was connected. Heck, maybe not to the TDC directly, maybe there was a readout next to it on the conn and Joe sailor entered it into the TDC, but this is not the point, the point is that bearing was TRANSMITTED INDIVIDUALLY. And in case of the TBT via a button (because the thing was on the bridge while the TDC was below). Check the quote I provided above.
With the periscope I think there was a readout on the gizzmo itself which could be read by a bystander when the CO/XO said BEARING - MARK. I could digg it up as well, but it would be pointless - since the point is that BEARING was a seperate and independent entry into the TDC, no matter how that entry was exactly done in the end.

There IS a definitive source online (no, not SH1!) for all these types of quesitons:


C. TARGET DESIGNATION SYSTEM 14C1. General. 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 2 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. The indicators at the plotting stations show the true as well as the relative bearing. A buzzer system with hand contactors at the transmitting stations and buzzers at the plotting stations, radar, and TDC is provided for indicating when the transmitter is on the bearing of the target. A set of rotary cutout switches is located at the TDC so that the operator may shift the bearing indicators to the transmitter that is to furnish the bearings. The circuit designation is GT. It is energized from the a.c. bus by a fused switch on the I.C. switchboard. Own course input for the indicators that show the true as well as the relative bearing is obtained from the gyrocompass repeater panel through a rotary switch. 14C2. 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. 14C3. Target bearing indicators. These instruments, when energized and connected to a transmitter, indicate the bearing as transmitted by the target bearing transmitters. Their construction is similar to any other simple selsyn indicating device. The type installed at the plotting stations in the conning tower and in the
control room indicate the true as well as the relative bearing by means of a second dial which receives from the gyro system and indicates own course. The type used at the TDC shows the relative bearing only, but utilizes 2 dials, coarse and fine, so that increased accuracy is gained. An additional indicator showing both the true and the relative bearing is located at the radar to aid in coaching the operator of this latter instrument on the bearing of the target. This is a coarse reading instrument, its dial being graduated in 5-degree increments. Selector switches are provided at the TDC so that various indicators may be switched to the transmitter that is to furnish the bearing.

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

There was a button on the TBT(s). I've seen it, on the bridge of USS Parche, sitting in the middle of SubBase Pearl, maintained exactly as she was when Red Ramage drove into history.

The problem with the game is the player has to fill multiple roles. In reality a highly trained officer, the TDC operator, input all these inputs and tracked the math of the solution against what the Approach Officer was seeing. Bearings don't lie; if the TDC wasn't tracking one of the other three inputs HAD to be wrong. The TDC operator was accountable for the data going in and reporting data coming out. It was up to him to decide if he wanted to input a radar bearing or a TBT bearing, or both. The readout at his station let him choose and always made it clear which he was reading.

Modern incarnations of the Type II scope--like the one I used in 1982--have a bearing transmit button on one handle. But the above source seems to indicate WWII scopes didn't have this. The scope assistant doing "the dance" read the bearing off the bearing ring in the overhead when the Old Man said "Mark". But he didn't announce it until the scope was headed down. When the Approach Officer talks EVERYBODY shuts up.

As for observations, a classic initial observation has three parts: "Bearing, Mark! Range, Mark! AOB is ____. Down scope." Always in that order, always in that terminology. Always. My battlestation was three feet from the scopes; I heard hundreds of these over the years. It's drilled, and drilled, and drilled into the FC party.

That said, those were initial looks. After the first AOB call there's no need to repeat it unless there's a zig or the AO realizes he made a bad call. After the first observation a track was established and subsequent observations often had only the first two data elements. Once the AO was satisfied the TDC solution was tracking he often only did bearings. The final look before launch was very often only a bearing mark, the TDC operator would announce "Solution tracking!", and the fish was on its way.

The SH series, by necessity in the state of the art, makes the player busier than a one-armed paper-hanger. It doesn't begin to reproduce the party enviro of real life where the AO had several smart people backing him up and helping find the solution.

[AVGWarhawk]

The SH series, by necessity in the state of the art, makes the player busier than a one-armed paper-hanger. It doesn't begin to reproduce the party enviro of real life where the AO had several smart people backing him up and helping find the solution.

Excellent and dead on. So we do what we can and we have our little helpers because we are just one Skipper with a bunch of AI crew that do just about nothing. Still, I like the manual set up for TDC and automatic TDC just point and shoot is not fun.

[heartc]

Awesome info Snowman999, thanks for sharing. You really need to speak up more often.

On the stuff you quoted, in fact the part about the TBT is the same word for word as in the link with the TBT picture I provided, seems like they used your reference as a source there.

As to "Bearing, Mark! Range, Mark! AOB is ____. Down scope."

- I would think this is what we are basicly simulating when we send Range, AOB and speed via the upper right hand dial in scope / TBT view. Well, maybe except for speed, as this was indeed mostly plotted by the FC party from early on most of the time, and this would be simulated only if the stopwatch thingy would be working. Is it in 1.2? I didn't d/l the patch yet and have read no clear word on that point.

[Snowman999]

Awesome info Snowman999, thanks for sharing. You really need to speak up more often.

Aw, shucks. <g> There are lots of guys here with more experience than I had. Look in the "Who served in a sub" thread.

On the stuff you quoted, in fact the part about the TBT is the same word for word as in the link with the TBT picture I provided, seems like they used your reference as a source there.

That manual set is priceless. Every sub simmer should at least flip through it to understand just how complex these beasts were on a mechanical basis. I'm amazed at the solutions they achieved with electro-mechanicals that we would flip off with digital now. There were some real engineers at EB and BuShips in those days.

As to "Bearing, Mark! Range, Mark! AOB is ____. Down scope."

- I would think this is what we are basicly simulating when we send Range, AOB and speed via the upper right hand dial in scope / TBT view.

Essentially, yes. But the game doesn't really model how critical short scope exposures were. The AO needed to do the data collection AND get a tactical picture in 5-7 seconds on an initial, and 3-5 seconds on subsequent, looks.

Well, maybe except for speed, as this was indeed mostly plotted by the FC party from early on most of the time, and this would be simulated only if the stopwatch thingy would be working.

Speed is the one place the game is just wrong. Speed came from class ID limits, normal Japanese convoy behavior, and most often from sonar turn counts. Taking three observations and doing a mo-board is nice theory, but many targets would have come and gone while you were dogging it between looks. (Especially IJN targets; they didn't mosey along.)

Also, the observation itself is formal, short, and data-rich because those seconds of scope exposure were priceless and very dangerous. Once the scope was down the AO would converse with his party. He'd do the target ID then ("Looks like a medium coastal freighter, smoking badly, deep laden.") He'd describe the escort screen, as much as he could. He'd lean over the plot and help the plotter rough in the formation, and begin a zig tracking plan. Then he'd do the second onservation. If a zig had happened it got interesting quickly.

Ned Beach's books have some of the best choregraphy for this process I know of. He was a far beter writer than O'Kane. O'Kane was probably the best AO the USN ever produced, but his writing is robotic. Beach gives more flavor IMO.

[heartc]

Originally Posted by Snowman999

Speed is the one place the game is just wrong. Speed came from class ID limits, normal Japanese convoy behavior, and most often from sonar turn counts. Taking three observations and doing a mo-board is nice theory, but many targets would have come and gone while you were dogging it between looks. (Especially IJN targets; they didn't mosey along.)

Yeah. Though I've read in Capt. Beach's book that once radar was available and a contact established, the plotting party would go to work and of course also gather speed in the process, that's what I meant with "from early on". He also often mentions turn counts, yes. In fact, that should be possible in SHIV, too - I remember a community member produced a table with different ship types, turncounts vs speed for SHIII. I never tried it myself but reportedly it worked.

Ned Beach's books have some of the best choregraphy for this process I know of. He was a far beter writer than O'Kane. O'Kane was probably the best AO the USN ever produced, but his writing is robotic. Beach gives more flavor IMO.

Beach's book "Submarine!" is in fact the only one I have on subs. I picked it up in a Second Hand English bookstore here in Munich. Yes, I know I need to get "Silent Victory", "Run Silent, Run Deep" and whatnot, too.