Kanmon Undersea Railway Tunnel & the Invasion of Japan

Discussions on all aspects of the Japanese Empire, from the capture of Taiwan until the end of the Second World War.
Mil-tech Bard
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Re: Kanmon Undersea Railway Tunnel & the Invasion of Japan

Post by Mil-tech Bard » 01 Dec 2014 21:36

Below is an earlier, smaller, version of the Javaman based on the USAAF A-3 target boat.
Javaman -Type A-3 Target - 1 June 1945.jpg
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Wellgunde
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Re: Kanmon Undersea Railway Tunnel & the Invasion of Japan

Post by Wellgunde » 02 Dec 2014 06:49

Mil-tech, my hat is off to you. I can't imagine that digging this stuff out of NARA was either quick or easy.
γνώθι σαυτόν

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Re: Kanmon Undersea Railway Tunnel & the Invasion of Japan

Post by smallag » 18 Feb 2019 17:04

Sorry for restarting this thread so many years afterwards. I do PT Boat research and have been trying to find the related history of the attached photos of what I believe is Elco hull##3683 that was completed as just a hull in 1944. Photos say "PT486", but believe that refers to the contract number (NObs-1006 PT486) for production of this set of 60 boats plus one since the actual PT486 was busy operating up in Rhode Island with Ron 4 during these dates. Since the 85 foot ARBs were brand new and this particular Elco hull was added to an existing construction contract around March-April 44, I'm thinking this might be related to the Javaman Project. I'm going to be headed to NARA in several weeks and will advice if I find anything. The Elco hull that was part of the contract was later designated small boat C-36204.
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Takao
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Re: Kanmon Undersea Railway Tunnel & the Invasion of Japan

Post by Takao » 18 Feb 2019 22:01

Have you tried contacting the Mystic Seaport Museum to see what they have in their collections?
https://research.mysticseaport.org/coll/coll213/

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Re: Kanmon Undersea Railway Tunnel & the Invasion of Japan

Post by smallag » 15 Mar 2019 15:37

Thanks for the pointer! Back in 1996 Mystic gave all the Elco "Military" Records that had been passed to them by EB over to the Naval War College Archives. The documentation mentioning the contract mod to 1006 (adding the spare hull) and small boat designation came from that collection at NWC, so a few bits and pieces.

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Re: Kanmon Undersea Railway Tunnel & the Invasion of Japan

Post by Mil-tech Bard » 03 Apr 2019 20:49

smallag,

This google books link may be of interest to you.

Unmanned Systems of World Wars I and II
By H. R. Everett
https://books.google.com/books?id=odjgC ... AN&f=false


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Re: Kanmon Undersea Railway Tunnel & the Invasion of Japan

Post by Mil-tech Bard » 03 Apr 2019 20:58

smallag,


The following is transcribed from a document in the National Archives.

---------------------
3 May 1945

Flight Section
Project Javaman
W.F. Nolan, Major, AC
Plans for Project Javaman

1. The following system is to be used by this command to assure complete control of missiles at all times. (The following terminology will be used in referring to planes and boats)

a. Two boats which are controlled by one aircraft will be referred to as a "group"
b. Two aircraft which control the group will be referred to as a "flight"
c. In an attack using four boats and four aircraft they will be referred to as "two groups of boats" and “two flights of aircraft” (Group No. 1 will always be controlled by flight No. 1. Group No. 2 will be controlled by flight No. 2 etc.)
d. The planes will be numbered within the flights as No. 1 and No. 2 in the No. 1 flight, No. 3 and No. 4 in the No. 2 flight, etc. The boats will be numbered within the groups as A and B in the No. 1 Group, C and D in No. 2 Group, etc.
1-a. A minimum of one aircraft for each missile will be used.
(a) At least three means of communication between planes will be used with a standby emergency communication system

2. The plans of operation will be as follows: Two B-17G type aircraft will be equipped with identical installations so that either of these two aircraft may maintain full control of the two missiles to which they are assigned. Two aircraft will take off together as a flight and fly loose formation, the lead ship to be the No. 1 control plane and to run the operation completely. The No. 2 aircraft in the flight will be an auxiliary aircraft in direct contact with No. 1 and will be able to take control of either or both missiles at any time if ordered to do so by No. 1 aircraft. This will give us a 100% standby control system, in addition the No. 2 aircraft will act as an escort plane to protect No. 1, and until such time as No. 2 aircraft actually participates in the operation, it will be its primary duty to protect the control plane at all costs.

3. The following is a rough outline of an operation using four missiles. Four B-17G type aircraft will be organized into two operating units which will be called “flights”. They are to be designated as No. 1 flight and No. 2 flight, and the planes within these flights will be designated as No. 1 and No. 2 for the No. 1 flight and as No. 3 and No. 4 for the No. 2 flight. The No. 1 flight consisting of No. 1 and No. 2 aircraft will have control of the two lead boats to be designated as No. 1 group, which will consist of A boat and B boat. The No. 1 flight will take off at zero hour and fly in loose formation to the point of rendezvous. The No. 2 flight will take off at zero plus 10 and proceed to the point of rendezvous. The difference in altitude of 1000 feet will be maintained between flights for safety reasons. The No. 1 flight will always fly at even altitudes. The No. 2 flight will always fly at odd altitudes. The No. 2 plane of No. 1 flight and the No. 4 plane of No. 2 flight will be auxiliary aircraft and will not be used unless trouble develops in No. 1 or No. 3 aircraft. The two aircraft which compose the flight will be in visible contact with each other at all times, and in the event that No. 1 aircraft has difficulty operating either of its missiles, it will contact No. 2 aircraft by one of the following methods in the order listed –––

(1) No. 1 aircraft will fly alongside No. 2 aircraft and wobble its wings. This will mean that No. 2 aircraft will take control of A missile. If No. 1 aircraft comes alongside No. 2 aircraft and fishtails, this will mean that No. 2 aircraft will take control of B missile.
(2) By shooting flares into the air, the green flare would mean that No. 2 aircraft should take control of a missile. A red flare would mean that No. 2 aircraft should take control of B missile.
(3) Contact between radio operators by use of Morse Code "in code"
(4) As a last resort verbal contact by use of SCR 522 using coded phrases may be used. (It is believed that SCR 522 is being monitored by the enemy.)
(5) In regard to sub-paragraphs (1) and (2), in the event that both indications are used this will mean that No. 2 aircraft should assume control of both missiles and take the lead position. No. 1 aircraft would then fly wing position and protect No. 2 aircraft. In other words if No. 1 aircraft fired both a red and green flare, it would indicate that No. 2 aircraft should assume complete control of both missiles.

4. After the targets have been destroyed by the missile, the lead aircrafts of such flight will take a heading towards the base and rock the wings very slowly. This will indicate to the second aircraft that the mission is completed. Upon the return trip to the base, each aircraft will proceed as an individual plane and not as a flight due to the gasoline consumption flying in loose formation. However, it is advisable to stay as close to each other as practicable in the event of an attack.

For Chief, Special Projects Office:

WILLIAM F. NOLAN
Executive Officer
Project Javaman

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Re: Kanmon Undersea Railway Tunnel & the Invasion of Japan

Post by Mil-tech Bard » 03 Apr 2019 21:08

Since the 85 foot ARBs were brand new and this particular Elco hull was added to an existing construction contract around March-April 44, I'm thinking this might be related to the Javaman Project.
There were to be a total of 12 of the 85-ft ARB were in the Campbell/Javaman program in Nov 1944.

At that date - Nov 1944 -- only six had been delivered to the OSS for modification.

The earlier A-2 drone in the Critical Past video links used depth charges. The use of demolition blocks inside an iron (or aluminum) frame was to be standard in 1945 for the 85 foot ARB drone.

The date of your photos and the frame with demo boxes is spot-on in line with that information.

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Re: Kanmon Undersea Railway Tunnel & the Invasion of Japan

Post by ChristopherPerrien » 22 Apr 2019 02:35

OK , I got to say it as I should have said way back , when I figured some Grand Slam/Tall boy bombing might have been in order to collapse this under sea railway tunnel. I dismissed the possibility of an explosive filled boat of 25 tons or whatever as being capable of collapsing this tunnel as it makes no sense.

From past history alone, you would think think many of the dudes involved with this Javaman project, would have known of the failures of boat-loaded explosives to accomplish ANYTHING in myriad examples . The English tried it against the Dutch IIRC , it failed. The US tried it against the Tripoli pirates, it failed. The US tried it in the Civil War against Ft Moultrie, it failed again. And IIRC both the British and the Americans tried it a couple other times too in various other wars, failed every time. The only success was the Nazaire Raid(the second one) in 300+ years of naval land warfare. Yes , the St Messines mines worked too, but those were underground tamped explosives , in no way similar to here. Even the Campbeltown's explosion was touching the gates it was meant to destroy . Add some distance by air for an explosion to travel or a few feet of water to travel though nothing happens

Simply , a weight of explosives detonated in the air accomplishes nothing . The ONLY way this Javaman concept could have succeeded was sinking it on top on the tunnel and then detonating it. Then with the tamping of the weight of the sea , yea I could see it working. But otherwise detonating a boatload of explosives or even a shipload of explosives on the water's surface stood almost no chance of penetrating even a few feet of water to a tunnel (besides the tunnel being buried) or a shock wave traveling to collapse an entrance on land .

Neither way makes any sense , and would I suspect any engineer of explosives , any student of military history , or any idiot who had half a clue about either, back at the end of WWII , would have known that the Javaman Project was absolutely useless and stood no chance and stood no chance of success against this undersea target.
That was why Tall by /GrandSlam made the only sense to me, and I got to wonder what was the OSS /CIA ? or whoever cooked up the Javaman project was actually thinking about (keeping their cousin's government contract alive ?) because the ability of a 25 ton explosive PT to collapse a lined railway tunnel under 25-50 feet of water plus x feet of dirt seems entirely impossible. The failure of the Ft. Moultrie explosion was a lot closer to them than it was to me a few years ago. I got to wonder .

Javaman? MIC /CIA shenanigans to scam $$$, perhaps they were thinking of a target elsewhere(not Japan, maybe Joe Kennedy's Sr. yacht for all I know, Hirohito's ? , I just don't see Javaman being a viable project to destroy this Kammon Railway. It was not going to work, centuries of earlier failures would have made that apparent to at least a few reasonable heads. What was "Javaman" really about at that time?

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Re: Kanmon Undersea Railway Tunnel & the Invasion of Japan

Post by Mil-tech Bard » 30 Apr 2019 13:48

ChristopherPerrien

Via the Nimitz Graybook war diary Vol. 7 (1 Jul 1945 - 31 Aug 1945)
1. Javaman was not cancelled and replaced by the RAF attack for
Kenney's FEAF. It would happen _simultaneously_ with the strike by
the RAF on the Kanmon tunnel complex entrances on either side of the
Shimonoseki Straits.

2. There would be six ARB boats, with all six disguised as Japanese
"Luggers" or "Sea Trucks. Four would be missiles; two would be
return/recovery boats.

3. The "missile boats" in addition to the active IR television to
spot the Japanese marker buoys, would also have magnetic anomaly
detectors
to park directly over the tunnel prior to scuttling.

4. The FEAF would maintain a continual combat air patrol over the OSS
Javaman flotilla to protect them on their trip from Okinawa, and not
just from the Japanese, but from friendly fire from marauding American
fighter-bomber patrols.
The above information was at pages 183 -thru- 185 of 303.

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Re: Kanmon Undersea Railway Tunnel & the Invasion of Japan

Post by ChristopherPerrien » 01 May 2019 07:26

Mil-tech Bard wrote:
30 Apr 2019 13:48

3. The "missile boats" in addition to the active IR television to
spot the Japanese marker buoys, would also have magnetic anomaly
detectors
to park directly over the tunnel prior to scuttling.
Well good, TY for looking, finding, and writing that up

The "prior to scuttling " , seems to say they would have sunk them on top of the tunnel. So I give them a pass, as I said that "might work".

I will note , Phylo did note the issue of the dampening effect of detonating the boats on the susrface
"IIRC the tunnel itself was a minimum of ten metres below the sea floor...which in turn was a minimum of eighteen metres deep? How was the remote controlled boat bomb option supposed to deal with the cushioning effect of over 50 feet of water? Even if it was carrying four tons of HE? '

I don't recall if scuttling itself was noted back in the topic as a solution to this, after many so years since reading/researching this topic in any detail. Was this "presupposed " and/or something I missed back then about MAD's and "sinking" these boats on top on the tunnel? I don't recall reading any info/ documents to these aspects. Back then i thought either A) , they were going to be detonated on the surface of the water above the tunnel or B) run onto the shore above the tunnel and detonated

And MAD back then? , To pin point it accurately . One spike might be a chunk of metal, sunk boat , or a mine. Drifted Japanese channel mines / shore invasion mines, or our own mag mines ? If we mined that channel with mag mines, hopefully those had set/functioning self destructs. Seem to recall something about a 1 week timer.

The list goes on as to the problems with successfully doing this-, with bomb boats, at night ,limited time, war time conditions , guarded pass, busy channel, plus using IR TV, plus remote control, plus accurate magnetic anomaly detection info, plus trying to accurately "scuttle " a boat at "open" sea , in X needed feet of sea above the bottom nearer the shoreline in the "vulnerable area" and hope it "sinks" right (wind , waves and particularly current in this area being a factor, plus wood boat, then getting this non-shape charge (a pile of box explosives) to function right , plus a bunch of other unks and unk-unks, plus the history of so many other "hair-brained" schemes to do something similar to this , just doesn't strike me as viable to really waste time/man-power on. Yea maybe a "fire-ship" explosive drone boat to crash into a moored ship or a dock maybe, like other drone boats. This? no ,It has Panjerdrum written all over it. Good thing the war ended , might have been another Aphrodite and got a few more people killed.

The plan to configure some B-29's or use some Lancaster's (much cheaper and faster) and Grand Slam/Tall-Boy "Bomb's Away", or just simply use 2000 lb GP bombs on B-29's on that large section of "vulnerable" tunnel both below the water for 900 feet ' and another 3500 feet or so of tunnel underground, seems much simpler,and viable than either Earth-quake bombs or Javaman boats And the fact that is lised so readily on the Target assessment map on page one of the topic,again makes me think the 'Javaman' project was for something else or Javaman was a cover itself for something else , like the TV radio control system development.Putting explosives on boats to blow up something was nothing new.

KISS rules :milwink:

Excuse me , for maybe "mucking up" this rather good study and info topic on the subject, I guess a little "churn" is alright, might catch someone's attention out on the net with more info or a connection to the topic, as has occurred in the past.

Regards,
Chris

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Re: Kanmon Undersea Railway Tunnel & the Invasion of Japan

Post by Mil-tech Bard » 03 May 2019 04:05

ChristopherPerrien

See this for end of WW2 detection experiments with MAD sensors:
https://apps.dtic.mil/dtic/tr/fulltext/u2/221590.pdf

Page 131 to 132
8.3 DETECTION OF COAST-ARTILLERY GUN BATTERIES

Descriptions from a friend of mine on that PDF --
Flights were made over the fortifications of Fort Hancock, New Jersey, which consist of two 16-inch guns, two batteries of two 12-inch guns per battery, a battery of two 6-inch guns, and a battery of disappearing 12- and 14-inch guns. Surprisingly large signals and low noise levels were obtained, assuring the detection of the 16-inch guns from an altitude of 1,300 feet. Measurements were made both with the standard detector and with the detector with less low-frequency response. The former is better suited for altitudes greater than 200 feet.

Figure 5 shows the signal obtained with the modified detector while flying at 1,025 feet over the 16-inch guns. At 1,325 feet an identifiable signal was also recorded with the standard detector. The 6-inch guns appear on the trace of Figure 6. The run shown on Figure 7 was intended to portray what a hedge-hopping aircraft would find white flying over coastal fortification. The flight path was not always directly over the targets. The objects causing the signals are labeled on the record.

The magnetic moments of the gun were estimated from extrapolation of the data from model experiments. They are:

16-inch guns 3.4 x 109 cgs each
12-inch guns 3.0 x 109 cgs per battery of two guns
6-inch guns 1.0 x 109 cgs for two guns

The airplane was also flown over a railroad gun and the moment was estimated to be 0.25 x 109 cgs. The battery of 12- and 14-inch disappearing guns gave a signal equivalent to a 0.25 x 109 cgs source. These last two values are questionable; the remaining magnetic moment calculations should be within a factor of two of the actual values. As was mentioned previously, there is little information available concerning the moments of steel structures such as these. However, it is to be expected that, as a result of being fired while parallel to the earth's magnetic field, a gun barrel might acquire a larger permanent magnetic moment than would be expected for other structures of similar size and weight.

They also tried using it to find military materiel: they had a MAD equipped plane fly over five near identical areas; and it correctly identified the single one of the five that had a very well camouflaged tank battalion.

The altitude they did their MAD tests against field equipment (tanks) was 125 ft or less.

For the Coast Guns, the easily discernible charts with good signal to noise ratios for analysis are:

16" gun battery at 1,000~ feet altitude @ 135 MPH
6" gun battery at 400 feet altitude @ 135 MPH

These are flying DIRECTLY over the targets.

They tested 230 feet @ 135 MPH in a simulated hedgehopping pattern against coastal defenses and found that the planes did not have to fly directly over the target to have them show up on MAD.
The implications for modern tank battalions versus MAD equipped drone swarms is left to the imagination of the reader.

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