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The Invasion of Japan, a Book Review

Discussion in 'The Pacific and CBI' started by belasar, Oct 23, 2015.

  1. ickysdad

    ickysdad Member

    Dec 18, 2008
    Likes Received:
    and per using smoke...

    T. Telenko12 hours ago

    Mr. Gray,

    Thanks for the link, but while the folks at Tank-net are usually pretty reliable, they are not in this case. I much better source.

    I have a copy of the US Army Ordnance 1,000 mile road test on the 39-inch grousers completed 8/5/1945 and approved as the following report on 9/5/1945.


    DATE 9-5-45 REPORT NO. PG-61901.110
    T.A.P.G. Project No. 668
    O.D.C. No. 72 COPY 3
    TITLE: Test of Special T80 Tracks Equipped with 39" Extended Grousers

    T. Telenko7 hours ago

    >>What does Anzio's defenses in February of 1945 have to do with it?

    A great deal.

    The Chemical Warfare Service was going to use Salerno and Anzio tactics of large area smoke screens and smoke haze to limit Kamikaze attacks during first few days of the invasion, and for longer term to block IJA artillery observations until the terrain over looking American troops was taken.

    This is what the CWS did to save Anzio from German Railway and heavy artillery From Colonel M. E. Barker CWS, "Smoke in Defense of a Vital Port", Coast Artillery Journal, Jan-Feb 1945, page 13.

    No attempt was made to lay down a dense smoke, but
    rather to generate a haze which would prevent the observer
    top of the building at Nettuno seeing through the haze
    well enough to pick up the details of the Littoria towers
    and the hill masses generally to the north of Cisterna.
    Thus it became necessary to operate the mechanical smoke
    generators at widely varying rates of fog oil consumption
    in order to accomplish this result with the minimum conumption
    of fuel. An inventive sergeant in the maintelance
    company soon developed a by-pass arrangement
    which enabled the mechanical smoke generator operator to
    vary the smoke consumption from thirty-five gallons per
    hour to 120 gallons per hour. In addition, three smoke
    pot emission points in hovels were laid out in the vicinity
    each mechanical smoke generator position so that when
    necessary the smoke from the mechanical generators could
    supplemented or replaced by HC smoke from the smoke
    pots. Also, in the rare cases when a north wind blew in
    the daytime, the smoke pot installations were operated to
    help conceal the exact location of the mechanical smoke
    generators and thus reduce the effect of German artillerv
    fire which was directed frequently against individual mech
    anical generators."


    After the various units became accustomed to the use
    of smoke in the area, they simply moved their installations
    so as to take advantage of the smoke screen and to get
    some little distance away from the individual generators.
    From time to time complaints were submitted on the effect
    of the screen and in some cases a movement of the generator
    solved the problem, but in other cases the unit concerned
    was required to move its installation. The smoke screen
    required constant observation from the smoke control
    tower at Nettuno which had to be occupied day and night.
    Linesmen had to be on the job twenty-four hours a day to
    keep the telephone lines radiating out from the control
    tower in working order. Radio was used only in case of
    necessity when the telephone lines were out. The corner
    of the tower was knocked off one day by a 170 shell and
    several days later other 170's went through the building
    below the tower, but the observers stayed on the job."

    And these were the Operation Olympic plans the CWS had in motion from Pages 425 & 426 of "Chemicals in Combat"

    The Technical Services
    Brooks E. Kleber
    Dale Birdsell

    "Although the planning for the invasion of Kyushu, the southernmost
    island of the homeland of the enemy, had not been completed
    when Japan surrendered, it appeared certain that smoke generator
    troops would have seen extensive use had the invasion been mounted.
    Colonel Copthorne, now Chemical Officer, Army Forces, Pacific, arranged
    with representatives of the operations officer of his headquarters
    and with the commander of Amphibious Forces, Pacific Fleet, for the
    use of five chemical smoke generator companies during the early stages
    of Olympic, as the operation was dubbed. Earmarked for the eastern
    shore of Kyushu were the three companies of the 28th Smoke Generator
    Battalion. The two quartermaster truck companies which had
    formerly been the 70th and 170th Smoke Generator Companies were
    to be reconverted to smoke units and earmarked for operations on the
    western shore of Kyushu. During the initial stage of the operation
    and under control of the Navy, the companies were to screen ship
    concentrations, harbors, and beaches. Once the invasion forces had
    successfully landed, smoke troops would revert to Army control. How
    these units were to be assigned in support of tactical operations on
    Kyushu was still a matter of conjecture when the war came to an end.
    Upon orders of AFPAC, Eighth Army prepared a study on the use
    of smoke troops in land operations on the island. It recommended in
    July 1945 that twelve M2 mechanical generators be issued to the
    chemical service platoon assigned to each combat division and that
    two smoke generator battalions, each with four companies, be redeployed
    from Europe and assigned, one each, to the two invading

    Colonel Copthorne approved the idea of giving mechanical smoke
    generators to chemical service platoons, calling attention to the growing
    tendency of combat troops to demand larger and larger smoke screens
    and arguing that the use of fog oil by the service platoon would reduce
    the tonnage of mortar and artillery smoke ammunition. The chemical
    officer of Sixth Army, Colonel Burns, opposed the plan. He felt that
    the chemical service platoons had neither the men nor the transportation
    for the conduct of screening operations. Moreover, he considered
    impractical any attempt to substitute a fog oil screen for a projected
    smoke screen because they served "different tactical purposes."
    There could be no doubt that chemical service platoons in the combat
    area were fully occupied in the supply and maintenance of chemical
    supplies and were already short of transportation facilities. But Burns's
    statement concerning tactical screening ran counter to the experience
    of U.S. forces in Europe who frequently used fog oil to save mortar and
    artillery ammunition. V-J Day found still unanswered this question
    of how the combat divisions"

    For the Chemical Smoke Generator companies referred to above, see the following document from "Combined Arms Research Library Digital Library"




    Page 16

    "2. Inactivations. Fifteen SG companies in the ZI and Southwest Pacific Theater were disbanded or converted between March and November 1944. 33/
    This action was chiefly due to a lessened demand for port-screening operations because of the decline in both Japanese and German air activities, and to the urgent manpower needs of the War Department.34/
    At the end of the war in Europe, 25 SG units were still active. When the decline of enemy air power obviated the need for rear-area smoke operations in ETO, the SG units were not disbanded but were assigned to other duties, if not needed for forward-area smoke missions.35/
    In January 1945, the War Department ordered the disbandment of two SG companies in ETO, but the order was not carried out.


    33/ See Table No. 1. Two units, the 70th and 170th SG Companies were disbanded in SWPA (Southwest Pacific Area); the other 13 in ZI.

    34/ The majority of the inactivated SG companies were converted into Engineer dump-truck units. Only one was converted to another type chemical unit.

    35/ It appears that the projected plans for the Rhine crossing was a factor in not disbanding SG units in ETO after July 1944."

    page 17

    "After the invasion of Leyte it appeared that smoke generator units were going to be needed in futher operations against Japan and the Headquarters and Headquarters Detachment, 28th Chemical Smoke Generator Battalion, were activated at Camp Sibert during January 1945. The battalion headquarters was sent to POA (Pacific Ocean Area) in April 1945, where it was assigned to the Tenth Army and participated in the Ryukyus Campaign, but not in smoke operations. The battalion would probably have been active in smoke operations had the invasion of Kyushu been made."

    The VMAC was going to get two "Negro" or "Colored" Smoke Generator Companies (the 70th and 170th) to cover their landings and the three US Army Corps would get smoke generators to either be used by their Divisional Chemical Warfare Service platoons or by additional Smoke Generator companies.

    The 6th Army was still staffing that as the Pacific War closed.
  2. lwd

    lwd Ace

    Jul 24, 2007
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    It doesn't address how the smoke fields would impact the suicide surface or submarine craft though. Once the landings are well underway I can see using a fair amount of smoke but while the landing craft are unloading and heading toward shore and close fire support is necessary the smoke could be a serious problem as well.

    As for trafficablity. I've seen studies on some of the more recent platforms and rice paddies are still a serious problem. The longer grousers may well have increased to mobility considerably but still not allowed for easyily transiting rice paddies.
  3. ickysdad

    ickysdad Member

    Dec 18, 2008
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    In reply to your post on Nov 22, 2015 4:02:05 PM PST
    T. Telenko says:

    Mr. Gray,

    The American military loves technological solutions. In 1945 it had one for firing naval gunfire through smoke screens. It was called the Radar beacon. They were deployed with Marine JASCO units at Iwo jima and Okinawa and with the US Army Operation Dragoon Landings in Southern France.

    They were not used because in France and Okiawa the
    Germans and Japanese didn't fight for the beaches. At Iwo Jima, the island was so small, the beaches so congested, and the air threat so minimal compared to Olympic, that 3,000 yard optical pointer fire control was used instead.

    At Kyushu, the beached were much larger and the need to use smoke a lot more pressing.

    See the following longs and clipped text for background.


    No. 11 in a Series of Amphibious Operations
    October 1945.
    "Amphibious Operations--Naval Gunfire Support" is approved and published for instructional purposes in the Marine Corps Schools.

    "Each infantry regiment requires one naval gunfire liaison team consisting of:

    1. Regimental naval gunfire liaison officer.

    2. Radio team (for communication with the corps naval gunfire officer, division naval gunfire officer, and battalion shore fire control parties and the headquarters ship).


    3. Wire team (for communication between the radio and the naval gunfire liaison officer).
    4. Radar beacon team.

    c. Each infantry division requires one naval gunfire team consisting of:

    1. Division naval gunfire officer (Marine artillery officer of field grade, specially trained in naval gunfire support, not organic to JASCO but an assistant G-3).

    2. Assistant division naval gunfire officer (naval gunfire liaison officer; officer in charge, shore fire control section, assault signal company).

    3. Radio team (for communication with the corps naval gunfire officer, regimental naval gunfire liaison officers, and the headquarters ship).

    4. Radar beacon team."

    and later --

    "Radar beacon employment.--Radar beacon teams are supplied to shore fire control parties for the purpose of establishing and maintaining the gun-target line. The beacon is a directional, line-of-sight instrument which may be located by the ship, the location being employed exactly as are the base point in artillery or point Oboe in naval bombardment. Once the beacon is operating, the ship's fire control radar is trained on it, offsets applied, and firing begun. Radar beacon teams are assigned to shore fire control parties upon request."

    Radar Beacons--RACON

    "...The delay in the Mark 1 beacon is approximately one microsecond, which causes all the indicated ranges to be approximately 150 yards longer than the true range. Therefore, in using beacons in connection with shore bombardment, the inherent error must be determined, and the error subtracted from the ranges indicated on the radar.

    Since a radar that is used to challenge a beacon cannot be used simultaneously as a detection device, it is not possible to spot the fall of shot with a radar while observing beacon responses on it. The Mark 4 and Mark 12 radars have rather poor bearing resolution, which makes them of limited use in ranging on land. With either the Mark 1 or Mark 2 racons available, the utility of these radars would be considerably increased in shore bombardment actions. Any radar spotting that is to be done can be performed by some radar other than the one observing the racon responses.

    After sufficient practice, it is claimed that the technician can retune a Mark 4 fire control radar for normal radar operation in about 10 seconds. Thus, using this radar for interrogating a beacon does not limit to any great extent the use of the equipment as a radar. If retuning from beacon to radar is to be accomplished within this short time, however, the receiver sensitivity for the beacon response will be far less than for a radar echo. This difference is due to the use of radio-frequency amplifiers in the Mark 4 receiver. These amplifiers are either left tuned to the radar frequency or by-passed, reducing the radar receiver sensitivity for beacon responses in either case. If it were decided not to attempt to change back to normal radar operation


    very quickly, the beacon responses could be detected well beyond 25,000 yards. With radars that are provided with an Automatic Frequency Control Circuit (AFC) the receiver local oscillator can be manually tuned to the beacon response, and the radar retuned for normal operation almost instantly by turning on the AFC. This type of operation could be very helpful in extending the use of the radar.

    Since portable beacons must be supplied power from batteries, the useful life of the racon is limited by the life of the batteries. The Mark 1 Mod 1 racon weighs 100 pounds complete, of which 60 pounds are in batteries. With these batteries the racon can operate continuously for 6 hours. If half the weight of batteries is used, the set can operate continuously for only two and a half hours.

    The shore fire control party is considerably handicapped by having to carry equipment as heavy as the Mark 1 Mod 1 racon. The Mark 2 Mod 0 racon, which weighs only 40 pounds, was therefore developed to reduce the load. With the lighter equipment the shore fire control party will be enabled to get in position more quickly and to operate successfully over rougher terrain than would be possible with the heavier equipment."
    belasar likes this.
  4. ickysdad

    ickysdad Member

    Dec 18, 2008
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    and this....

    In reply to your post on Nov 22, 2015 3:37:38 PM PST
    T. Telenko says:

    And you're missing several point about the 450(+) German guns bigger than 75mm -- with Ammunition! -- and the Allies learning by doing.

    The Japanese suicide attack force based defense plans were all based upon being able to see the beaches and ships.

    The American forces were going to be hitting the Japanese with a battle tested smoke doctrine, new to the Japanese, using tactics and weapons they had never seen before.

    Exhibit A --

    OSRD 6428

    Dec 29, 1945

    Page 22

    At a meeting at Edgewood Arsenal on August 1, 1945, it was decided that
    a limited production of 12,000 venturi units would be started immediately.
    The fabrication was to be done by the Cleaver-Brooks Company
    with production tools. The fuel block and the final assembly of the
    units were to be made by the National Fireworks Company. Plans were
    also made to have the unit in full production at the rate of 100,000
    per month within 90 days. While the end of the war removed the
    immediate demand for this munition, the development will be continued
    as planned under the responsibility of the Chemical Warfare Service.</I>

    The E23 was type standardized after WW2 for the US Navy as a replacement for the standard and floating solid HC smoke agent pots.

    The E23 smoke pot was a oil based floating smoke pot intended for use as a expendable screening unit for naval and merchant ships with a non-toxic smoke (HC smoke pots used in this way at Leyte poisoned US Navy LST crews).

    Post war testing showed that these pots lasted from 10 to 15 minutes against a design requirement of 15 minutes. However, the smoke was not as immediately toxic as HC smoke and would have been a major factor in the anti-Kamikaze defenses of the US fleet off Japan as the Kyushu campaign wore on.
    belasar likes this.
  5. lwd

    lwd Ace

    Jul 24, 2007
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    Some of the most effective naval gunfire support was by DDs that visually acquired their targets. Smoke can inhibit the fire control teams from acquiring targets as well. I don't see how smoke would inconvience the suicide boats or subs much at all and could indeed give them plenty of cover. He also seams a bit to sure of the various technologies working exactly as planned. The US and indead the rest of the world were still learning what radar could and couldn't do during the war. My understanding is that the radar environment in the vacinity of the invasion beaches would be considerably less than benign.

    Looking at his smoke pot description. The smoke pots last at most 15 minutes which means 12,000 would last for 3,000 hours if you burned them one after the other. However if you are going to cover a fleet like the invasion fleet you would need hundreds to do a decent job. If it took even 300 then you would have about a days coverage for the fleet. If you consider that you wouldn't want gaps in the coverage then it would be more like 5 per hour or more rather than 4 indeed if 10 minutes was all they were getting out of some of them then it would be over 6 per hour. At 6 per our and 200 locations you get again 10 hours of coverage. Need 400 locations and you are down to 5. Then there's the thing about the Kamikaze attacks had been almost totally against war ships prior to the invasion. Would the smoke pots be protecting the war ships or the transports or both?
  6. mcoffee

    mcoffee Son-of-a-Gun(ner)

    Sep 25, 2009
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    Telenko is putting an awful lot of faith in smoke pots. The defenders at Ploesti had an extensive array of smoke generators surrounding the city and the 13 refineries. While they did make the job more difficult, the smoke pots did not stop the 15th AF from reducing the refineries to negligible production prior to the Red Army overrunning them on the ground.
    I'm sure Truman was advised 'hey, we have smoke pots! We don't need no stinkin' bomb'
  7. belasar

    belasar Court Jester

    May 9, 2010
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    I suspect that US planners saw smoke generation in much the same way the Romanian's did, as something that gave those on the sticky end a reason to believe that "everything possible" was being done to improve their chances of survival. If it worked fine and if not, it was worth the try. Remember that Allied planners still hoped that in the aftermath of Olympic Japanese leadership would conclude that defending the Tokyo plain was pointless and accept Potsdam. In this instance they would be used only once and few would quibble about how effective they were, at least in the short term.
  8. LRusso216

    LRusso216 Graybeard Staff Member

    Jan 5, 2009
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    I'm nearly done Downfall. A few things occurred to me as I read:
    1) Information about the Japanese buildup prior to Olympic was known to key personnel through intercepts of Magic and Ultra decrypts. Grew, MacArthur, Stinson and others knew that an American invasion would be a bloodbath. MacArthur in particular chose to ignore the evidence. For these people to claim otherwise later is disingenuous at best.
    2) The Japanese leadership was divided even after the atomic bomb fell on Hiroshima. The military wanted to continue fighting, and wanted to amend the Potsdam declaration, hoping to convince the people that Japan didn't lose, but chose to stop fighting. They also wanted to control the trial of "war crimes", and were adamant that there be no American occupation. Others wanted the continuation of the Imperial line, but otherwise accepted the Potsdam agreement.
    3) The governor of Nagasaki reported that casualties there were light after the second bomb fell. This erroneous report encouraged the war party to continue on.
    4) The "peace" overtures to the Soviets were nothing more than a ploy, a fact reiterated by Sato and Togo. Even the emperor knew that Konoe had nothing concrete to offer.

    I need time to digest all that I found here. Much of the data echoed what was written in Hell to Pay. In any case, I have not come across anything in either book that would cause me to alter my view that dropping the bomb was necessary. The prior destruction of Japanese cities did nothing to lead the militarists to end the fighting

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