Malinta Hill

[oozlefinch]

If you take a look at Armyjunk's schematic of the Land Defense Magazine, it shows a 25KW set installed there. That schematic is a small section of the Engineer Drawing for SL-8, a copy of which I have. FYI, SL-8 was a 60" SL, not a 36". I believe a 36" was originally installed in the small tunnel below SL-8 that later held a 3" gun.

[chadhill]

Oozlefinch, multiple independent accounts place the 240mm round penetrating the SL #8 air shaft and igniting the fuel of the SL generator. I do not have a reason to doubt those accounts. I have, however, wondered how LT Friedline and several of his men in the tunnel managed to survive the blast of a 440 pound projectile, until they succumbed to their burns and wounds later that day. One would tend to think they would have been killed instantly- with their shredded remains scattered throughout the tunnel, and down the hill outside below the SL balcony. The Japanese newsreel snapshot photo showing SL #8 reminded me of this again, since I was under the impression that it was destroyed. Yes fots, the SL may very well have been rendered unservicable after the explosion, but it appears to be standing upright and basically intact, and that puzzled me.


The following photos, courtesy fots2, may explain what happened. The first is taken on top of Malinta Hill, looking down into the SL #8 air shaft. The second photo is at the rear of the SL tunnel, looking up the air shaft. Notice that there are remains of a rebar net. My SWAG is that the 240mm round hit the net (or the walls of the air shaft above the net) and exploded before it could hit the floor of the tunnel.







This final photo, again courtesy fots2, was taken from the entrance of SL #8 tunnel and looks towards the rear, where the air shaft is located. Sunlight can be faintly seen at the far end of the tunnel. The concrete wall lining the tunnel is intact, even at the rear where the explosion was. This would seem to reinforce that the 240mm round detonated part way down the air shaft, rather than on the bottom at the end of the tunnel. Much of the blast force was absorbed by the rock walls of the air shaft, and some of it probably also exited back out the top of the air shaft on top of Malinta Hill. A reduced blast reached the fuel tank of the SL generator in the tunnel but still ruptured and ignited it, with fatal consequences for LT Friedline and his men.

[chadhill]

Very astute observation, fots, about the ceiling bracket. And I'm amazed you could produce a photo of it! I agree that the old land defense magazine would have been a good place to house the Crosely. In fact, it looks as if a passageway for an electrical power cord to the surface may have already existed from the days when the 25 KW generator was there, and I wonder if the pipe you found may have been the outlet for it:

(diagram courtesy armyjunk)



Thanks to information in the link below, found by pdh54 after exhaustive searching, I learned that 1.1 inch pom-poms had either electro-hydraulic, electro-mechanical, or amplidyne power drives. If I understand the material correctly, there was even a manual drive version or mode:

www.ibiblio.org/hyperwar/USN/Admin-Hist/075-Ordnance/075-Ord4R.html

* * * * *

Now, a correction to the b&w photo of a shipboard pom-pom gun that I posted above:



Rather than "azimuth gears", I've learned these gears were referred to as "slewing gears". On early model 1.1 inch pom-poms these gears actually slewed the entire four barrel gun package from side-to-side up to 30 degrees. The idea was that at extremely high barrel elevations the guns would be able to track an incoming aircraft (such as a dive bomber) without having to rotate the entire mount, which could throw the aim off. However, there was vibration inherent in this slewing mechanism and it was discarded on later models.


I just came across a very interesting entry dated October 2012 in another forum (network54.com) by Nelson Lawry, who I understand is a researcher and author. I do not have access to the 16th Naval District War Diary to independently verify his quotes. However, I have long heard rumors of the pom-pom gun traveling from Cavite to Mariveles before finally arriving at Corregidor, and Lawry's research may finally confirm it:

"At the very beginning of this year, I asked author John Gordon a number of questions about the use of American naval guns transferred to the U.S. Army and used in the Philippine Islands in WWII. As most in this forum know, my interests include both naval guns and the army's field artillery. The Philippines campaign of 1941-42 is a very fertile and fascinating one, because several older weapons, some staggeringly obsolete, saw their first and only U.S. combat use there. The British-designed Model 1917 75mm field gun (originally 18-pounder or 3.3-inch) and the 19th century Vickers-Maxim 2.95-inch mountain gun are examples of such pieces in American hands.

I have had a particular interest in the 1.1-inch pompom mount that made its way from Machina Wharf, Cavite Navy Yard, eventually to the top of Malinta Hill, Corregidor, where in army use it closed the vertical window in the heights of fire of the M3 3-inch antiaircraft guns and the .50-caliber AA machine guns. In John's 2011 book, Fighting for MacArthur: The Navy and Marine Corps' Desperate Defense of the Philippines, pages 67 and 177, he writes that the 1.1-inch AA gun moved directly from the wharf at Cavite into army hands on Corregidor, where it went onto Malinta Hill. When I questioned him on that point, writing that I had long understood the quad gun had been mounted at the navy's Mariveles Section Base for a period, he expressed doubt, declaring that the mount went to Corregidor on December 17, 1941, and moreover, that information came from the war diary of the 16th Naval District.

Well, I'm perplexed what version of said war diary John obtained, because I found the diary at Archives II, and it tells a completely different story. The 16th Naval District War Diary is available for only a finite period, from early December 1941 to mid-February 1942, and I shall quote precisely several entries. Those remarks within brackets are explanatory additions or summaries.

Dec. 9: "Luzon [Stevedoring Company] tug 'Ranger' reported in from Hong Kong this morning."
Dec. 10: [large scale air raid on Cavite Navy Yard, with some details]
Dec. 11: [An hour's inspection of the damage done at Cavite determined that the casualty rate was higher than expected, but the Optical Shop, Ordnance Storehouse, and Ammunition Depot were intact and not threatened by the fires still burning. Concern stated about the substantial number of 1-pdr, 3-pdr, 6-pdr, and 3-inch/23cal mounts within the Ordnance Storehouse and what to do with them. Nothing was written about any additional 1.1-inch AA quad mount(s) therein.]
Dec. 13: Handwritten notes marked "CinC" include the cryptic entry "Dewey's 1.1 gun (Ranger)", and on the margin the notation "Has been sent out Dec 16".
Dec. 14: A two-page numbered accounting with U.S. Navy Section Base, Mariveles, Bataan letterhead includes Item No. 10. "Send 1.1 with accessories", with the handwritten notation in margin, "will be sent", and Item No. 16. "Taking steps for security of DEWEY. Will leave her in readiness for maximum use consistent therewith."
Dec. 16: "Sent two lighter loads of of ammunition and other material to Mariveles."
Dec. 17: "Dispatched two more lighter loads of small arms ammunition to Mariveles. Also on lighter were one 1.1" gun and five .50 cal. machine guns."
Dec. 24: "Verbal orders were given to Colonel Howard to start demolition at Olongapo and evacuate that place of Naval and Marine personnel to Mariveles."
Jan 6: "Marines want 1.1" gun brought over from Mariveles."
Jan 12: "1.1" gun received from Mariveles has been turned over to the Army and is being installed on Malinta Hill."

The story is amply clear. The large drydock Dewey (YFD 1), in place since 1906 at the Naval Station Subic Bay, Olongapo, was at some point, just before or just after the outbreak of war, brought down to the Mariveles Section Base at the tip of the Bataan peninsula for greater protection. The 1.1-inch quad mount was intended to mount either on board the drydock or on a hill near her for antiaircraft defense. The mount was put aboard a lighter at Cavite on December 16th or 17th, and towed by tug, probably the Luzon Stevedoring Company's Ranger, to Mariveles. The pompom was (perhaps) mounted there for about a month, until the greater need for the mount was perceived over on Corregidor. In army hands, it was installed atop the appreciable elevation of Malinta Hill. Dewey was scuttled just before the surrender of the forces on Bataan in early April 1942 (though later recovered by the Japanese), and the 1.1-inch quad AA gun maybe once mounted to protect her was blasted and put out of action on the last day of that month".

This Corregidor arrival timeline tends to agree with the information given in COL Barr's history of Battery M, 60th CA (AA):

"A Navy 1.1 inch pompom gun originally intended for the U.S.S. Houston was installed on Malinta Hill about the latter part of January was assigned to Battery M. The heavy gun was brought up the hill under the direction of Maj. Crawford, the Bn C.O. who also solved the problem of installing the water cooling unit. Four men attached from other batteries in the third battalion helped make up the twelve man detail required to man it. Gunner Otto of the navy instructed the detail in the service of the piece. The work of sandbagging and camouflage was capably handled by Lt. Friedline who was placed in charge of the gun".

As well as with The Moore Report:

"Late in January, a 1.1-in quadruple mount, automatic weapon, formerly intended for the U.S.S Houston, was turned over to the Harbor Defenses by local authorities, together with several thousand rounds of ammunition. A special concrete base was constructed atop Malinta Hill on which the weapon was mounted and turned over to the Anti-aircraft Defense Command. No fire control director was available but each round of ammunition was tracer type.

This quadruple mount was in action a number of times particularly in the zone between the effective maximum and minimum ranges of .50~aliber machine guns and 3-in guns".

[fots2]

Chad, all your ideas sound reasonable to me. I wondered about the damage (or lack of it) inside the SL tunnel too. We should also note that the land defense magazine has no interior damage either. The rear entrance is destroyed but that was from a shell hit on the outside.

Oozlefinch, correct and correct. I don’t know why I put 36” SL there, it was 60” for sure. I will correct that error.

Thanks for pointing me in the right direction to find more information on SL#8.

Searchlight #8 Power Plant (at the time of installation in 1935)
Location: in obsolete Land Defense Magazine IV-S-1
Maximum demand KW: 19.25
Type and Size: St. 25W, set No.17705
Cable length and size: 338’, 4/0 (the cable must have followed the steps down to the SL)
Cable Type: 1-con., 4/0, 600V., RIA
In conduits or in air: in conduit

From all the sources that Chad refers to, I have a feeling that the generator was transferred to the rear of the SL shelter at some point but I have not read this anywhere. It is difficult to ignore the text of a Battery ‘M’ officer who was onsite in 1942 and described the scene shortly after the 240mm shell explosion.

[westernaus]

Hi all,
A bit more on those Pom Poms for those who are interested .
According to an article from the web site The Jerseyman dated 2006 . A survivor from the USS Houston ,Master Chief Electrician William J. Stewart , USN / RET. Who was one of the 368 survivors From USS Houston . A description of the weaponary on board ship was given which says there were four quadruple 1.1 Pom Poms .

[fots2]

Chad,

You have a good suggestion about the power cable. In armyjunk’s sketch, the power cable from the 25KW generator is shown to go half way up the steps then we do not see it any more. This is probably where the cable entered the conduit heading to SL#8. When the pompom was being installed, breaking into this conduit would be quite easy to add a cable between the Crosley engine/generator and the pompom.

[oozlefinch]

Chad, Col. Barr's notes are pretty persuasive, I must admit. Here's another SWAG (there certainly have been a bunch on this thread), maybe the 25KW generator remained in the Land Defense Magazine, and the Crosley generator was put in the SL tunnel, and that, together with it's gas, was what caused the fire. While the Army didn't always do the logical thing, it would seem to be easier to do that rather than move the 25KW and then put the Crosley in the bunker. Just SWAGing. I still haven't been able to find out why the (ventilation) shaft was so large. It was designed to be 6' square, a little large for ventilation only. A SWAG sez that they were thinking of doing a modification of SL-1 to increase its angle of sweep, and then decided it wouldn't work.

[chadhill]

Oozle, all the sources say the rigged Crosley powered the pom-pom and a 25 KW generator powered SL #8 inside the tunnel. I don't have any reason to question that, and placing the rigged motor nearby the weapon makes sense. But please keep those SWAGs coming!

BTW, Barr's date of April 30th is in error. The pom-pom gun and all three 75mm guns on top of Malinta Hill were taken out on April 29th.


Fots' finding of the pom-pom mount prompted me to update the notations on the aerial photo and diagram provided by armyjunk:






(Another SWAG is soon to follow...)

[oozlefinch]

Chad - my thought was that the SL generator was left in the Land Defense Bunker to power the SL, and the Crosley generator was put in the SL tunnel to power the pom-pom. The cables could have been run up the shaft to the gun. That way they only had one operation to do, not two. By the bye, do you have any SWAG as to why the shaft was designed so large?

[fots2]

Chad, I would agree that both the photo and sketch you posted are labeled correctly.

Oozlefinch, I wonder if the rebar sticking out 1/3 of way up the inside of the air shaft can be a hint as to the reason for the diameter of it. As a SWAG, could the rebar have supported a partial platform which was the intermediate level of a set of steps down into the Searchlight shelter? This would be a heck of a lot shorter and faster route for getting in and out of there than the path around the hillside. Maybe even an emergency exit.

Here are two more Searchlight #8 air shaft photos to help give you some ideas.