What Could Possibly Go Wrong… Searching for new roles for Submarines at the Dawn of the Cold War

Today’s post is by Nathaniel S. Patch, Reference Archivist at the National Archives in College Park, MD and Subject Matter Expert for Navy Records.

This fall I am going to be presenting a paper on the Navy’s development of the Hunter-Killer Submarine (SSK) and how they evolved the World War II submarine into more familiar submarines of today. In researching that paper, I was digging in Record Group 38: Records of the Chief of Naval Operations in Entry P 1204: Formerly Security Classified Correspondence of the Secretary of the Navy and Chief of Naval Operations (SECNAV/CNO) and I was finding a lot material relating to my topic under filing designation A16-3(17) relating to Anti-Submarine Operations, but being thorough I also looked in neighboring folders as well.  Going through a neighboring folder SS/A16-3 a photograph caught my eye.

I was very perplexed why a flame would be jetting straight up from the conning tower of a surfaced submarine. And there was a second picture, but I don’t want to ruin the surprise. I had many questions, so I looked more closely at the memorandum accompanying the photograph and they referred to “Flame Thrower, Development of.”

I continued to have questions, so I took a little diversion to explore this curiosity.

According to the paperwork with the pictures, the Chief of the Bureau of Ordnance was requested to initiate the investigation into the development of a flame thrower for a submarine. The letter dated July 15, 1948, went on to say that submarines were ideal because of being built with systems that utilized pressurized gases (life support) and that a weapon could be developed to fire a special fuel to a minimum of 500 yards away. Obviously, but clearly indicated that the weapon was to be mounted outside the pressure hull with a trainable nozzle.  

Okay?

The following letter, Flame Thrower for Submarine (S77-1(8)) dated August 18, 1948 from the Bureau of Ordnance noted a few particulars about current equipment. Specifically, that flame throwers only an effective range of 140 yards was available and the best range with experimental equipment was 200 yards. They could slightly increase the range by changing the thickness of the combustible gel fuel, enlarging the size of the nozzle and increasing the operating pressure of the fuel being sprayed out. However, in increasing the thickness of the gel the ease of ignition might be compromised. The US Army Chemical Corps was working on a new fuel that could be tested at a later date and that $10,000 of the fiscal 1950 budget was to be devoted to this project.

This was all very interesting but both letters failed to mention why the Navy wanted to do this. Submarines after the First World War were considered to be platforms of many different things. Some worked and some did not. From my work, I found examples where the French and the Japanese were able to launch aircraft from watertight compartments attached to the deck. The French and British experimented with this concept. The British built a submarine, the doomed HMS M-1, that had heavy,12-inch guns. And the French built the Surcouf with two 8-inch guns, and also had a floatplane too. There were plans by the US Navy to outfit submarines with a 16-inch gun to bombard enemy shores (that is going to be for another blog for later). During World War II, the Germans and Japanese converted submarines from being just torpedo boats to carrying cargo, fuel, and aircraft (Japanese). The US Navy took older “cruiser-submarines” and turned them into troop transports to land Marine Raiders. Then at the dawn of the Cold War, the US Navy did many experiments with reconfiguring submarines for different missions like picket-RADAR (SSR), cargo/fuel carrying (SSO), guided-missiles (SSG), troop carriers (SSP), and a few odd projects like a submarine with a wide after-deck platform that a helicopter could land on. Some of these ideas stuck around, but as technology changed and improved, some of these ideas faded into the annals of history. But in this free for all of testing the submarine platform for other missions, the flame thrower just never appeared in my studies. This is not to say the Navy never used flame throwers. During the Vietnam War as operations along the Mekong and Bassac Rivers were increasing the joint command of the Mobile Riverine Force (MRF) was established in 1967. The MRF converted Landing Craft, Mediums (LCMs) into all sorts of combat craft including one armed with a flame thrower called the “Zippo.”

So why a flame thrower on a submarine? That did not seem safe to me. In the early days of the US Submarine Force, submarines had gasoline powered engines, and in a tight confined space like the small pre-World War I submarines had, those fumes would collect and mix with the hydrogen gas made from the primitive batteries that were used to power the electric motors when submerged. Gas fumes and hydrogen gas mix is and was a recipe for disaster, and there were “flame outs” when all the compartments would ignite in a flash of fire and flame causing injuries and damage. So, I ask why the Sub Force would want to revisit this chapter of their history.

My brief investigation took me to the Bureau of Ships Secret Correspondence, 1948 (Entry UD 1017-Y) finding a proposal under filing designation S77-1 (Chemical Weapons) that was forwarded to the Chairman of the Submarine Weapons & Countermeasures Group from the Chairman of the Submarine Conference dated April 8, 1948 including five endorsements from the Commander, G. L. Street, Commanding Officer of the USS Requin (SS 481) part of Submarine Squadron 4 (SUBRON 4), which SUBRON 4 was tasked to develop pro-submarine operations like coordinated attacking (wolf-packing) as well as escaping, and evading anti-submarine efforts of the enemy, all the way to the office of the Commander-in-Chief, Atlantic Fleet, Admiral William H. P. Blandy.  They all praised the concept and encouraged its development.

The proposal that had been forwarded and praised came from Lieutenant Commander Frank. W. Allcorn III, a former officer of the USS Finback (SS 230) during World War II (small world), and at the time working at the Naval Reserve Officer Training Candidate program at Georgia Tech. During World War II, he served as Torpedo and Gunnery Officer aboard several submarines earning two silver stars, and later became Assistant Torpedo and Gunnery Officer to Commander, Submarine Forces, Pacific Fleet (COMSUBPAC) and during the war the Submarine Operations Research Group (SORG) had made a brief investigation into a flame thrower for a submarine after seeing the success of the Army and Marines equipping tanks with flame throwers and being able to defeat the enemy in hard to reach places. And Allcorn thought that this could be applied to the 1948 countermeasures for submarines in the opening of the Cold War.

Here was the explanation to this seemingly dangerous idea that would heat up the Cold War on frozen unforgiving seas. Allcorn, like many submarine officers, had been in the situation during World War II where Japanese anti-submarine forces (destroyers, destroyer-escorts, subchasers, or whatever they had to fight back) would take pursuit of a fleeing American submarine after attacking a convoy. A tactic that had been developed to make the Japanese break their pursuit was called the “down the throat” shot – basically firing a stern torpedo at close range to either hit the ship or make the enemy ship turn away. The proposed flame thrower could have squirted some flames as the enemy ship made her turn exposing the whole length of the vessel. In 1948, a submarine with a flame thrower could either challenge an enemy destroyer or while fleeing one could squirt some flames up and potentially catch the forward-throwing ordnance of the destroyer (like the Allied Hedgehogs) on fire making them explode or at least make the ship button up – visually blinding them to make an escape.

During the war, calculations were made suggesting that a submarine’s capacity of 3000 pounds per square inch (psi) air supply with a slightly thicker gel could make a flame thrower with a range of 1,000 to 1,400 yards. And as an added bonus, it was noted that fuel gel would continue to burn on the water as much as it would burn on the ship.

Another reason for the flamethrower was that a World War II submarine had deck guns, which were mostly used to sink smaller unprotected merchant ships that were too small to use a torpedo on. In fleeing an enemy destroyer, a submarine would have to surface for an extended period of time between surfacing and getting the deck guns ready to return fire where the submarine was exposed to continuous enemy fire.  Piping the flame thrower through the shears of the conning tower, the submarine could remain submerged (periscope depth) and spray the enemy ship with flames. And for the purposes of the 1948 program, this weapon would be ideal for RADAR picket submarines and medium speed attack submarines (unconverted World War II-era submarines).

This all sounds great and plausible, so why was this program not adopted? And why, despite all the glowing endorsements for a flame launching submarine, was I only finding a few documents here and there in CNO and Bureau of Ships records? From the second picture, which we will get too, I checked the submarine’s deck log, although I was not sure when the test took place. I guessed sometime between January 1948 (Allcorn’s proposal) and August 1948 (the memo and photographs). Given that this project was a little distraction, I did not want to do a deep-dive on this.  And I think the second photograph illustrates some of the problems with the project and possibly why it was not adopted. Flame throwers are not a blow torch – an open flame. They shoot – squirt gelatin or semi-solidified gasoline/diesel similar to Napalm and a propellant. So in the first picture the flames are shooting straight up… And what goes up must come down…

In this picture, the submarine’s hull number appears to be “307”, which would make her the USS Tilefish (SS 307). I reviewed the 1948 deck logs of the Tilefish in RG 24 in Entry P 118-A1: US Navy Deck Logs, 1941 to 1950 for this test, but only having a ballpark period between January and August (date of the report), I was unable to pin down the test or the results. I also combed through the Bureau of Ships and Bureau of Ordnance correspondence to see if I could find a final verdict, but alas I could not.  I will keep trying adding this interesting chapter in submarine history to my pod of white whales to chase, and the mind ablaze with anticipation as I continue to explore.