R-20 Album

Notes

All photos on this page are courtesy of the Vallejo Naval & Historical Museum in Vallejo, California and come to us via Mr. Darryl Baker. No picture on this page may be reused without permission.

Running On The Surface ~ Deck Gun Raised

The R-20 heading out to sea on exercises with sister ships seen ahead. The bow is dipping into the waves and washing over on to the deck. These early R-Class submarines were built with the retractable 3"/23 caliber deck guns. The gun in this photo is in the raised position. Normally the gun would be retracted into its waterproof housing to protect it from sea water.

This next photo in the sequence shows the wave covering the deck and putting the gun underwater. It was unusual to leave this particular gun in the raised position while proceeding on the surface at speed and in these kind of seas.

One of the major reasons to make the gun retractable was to protect it from seawater induced corrosion, reducing maintenance requirements. With the waves inundating it in this fashion, the gun would have required careful and intensive maintenance once the boat returned to port.

Other submarines, most likely squadron mates, can be seen directly ahead and off the port bow. It is possible that the boats were proceeding to a gunnery training area when these photos were taken.

The R-20 continues to pound through the swells, temporarily submerging the entire forward deck all the way up to the gun, whose circular shield can just be seen.

The R-20 continues driving through the ocean swells off the Southern California Coast. Probably for some Torpedo and maybe Gunnery practice.

The R-20 continues driving through the ocean swells off the Southern California Coast. Once again the swells have submerged the entire forward deck.

Running On The Surface ~ Deck Gun Housed

It is not known if this and the next photo were taken at the same time as the photos above. In this photo the gun has been retracted into a watertight tub that penetrated the pressure hull down into the forward battery room. The circular gun shield forms a watertight “hatch” that protected the gun breech and the elevation and training mechanisms. A tampion is inserted into the muzzle end to protect the rifled bore from corrosion.

Out of sight in this photo is the recoil dampening cylinder, which also penetrated the gun shield. It is behind the barrel. Lifelines and stanchions have been put in place on the edges of the deck to give the gun crew some level of protection from falling over the side.

Another angle looking almost directly forward on the deck with a good look at the gun barrel. The two tubes or pipes on the deck are the torpedo loading mast and boom in their stowed positions. Later, when the larger deck gun will replace this one, these will be stored on the after deck leaving more room to train and point the large weapon.

The large rectangular deck hatch is the opening into the superstructure giving access to the slanted torpedo loading hatch below it. It has a dual purpose. First, to act as a deck cover for the opening, and secondly to act as a slanted loading ramp for the torpedo to rest and slide on. Its hinges are on the after end of the hatch and it folds up and back making the ramp.

Firing a Torpedo

The R-20 fires a practice torpedo with a non-explosive water filled warhead from either her #1 or #3 torpedo tube. As it exits the tube, after approximately 100 or so feet, it broaches the surface before diving back to its set running depth.

The puff of "smoke" is actually steam, as the Mk 9 and Mk 10 Bliss-Leavitt torpedoes used by the R-boats had a wet-heater type engine. This engine used an alcohol fueled flame to heat water into steam, which then spun the turbine to turn a dual contra-rotating propeller.

The weapon left a trail of combustion gases and steam in its wake, creating the characteristic white trail behind it. If the weapon broached it would leave a puff of steam in the air. Broaching was neither intended nor desired, as it gave warning to the target of the approaching torpedo.

These torpedoes had notoriously finicky depth keeping mechanisms, sometimes following a "sine wave" style up and down course to the target, with obvious negative implications to accuracy.

As the R-20 continues running on her assigned course, following the fired torpedo, its track of exhaust bubbles spreads out behind it. The next job for the R-20 will be to locate the torpedo and hoist it back aboard. It is then carefully lowered down into the torpedo room to be returned to the Naval Station for overhaul by the torpedo shop, and will be eventually reused.

The large wing-like array on the bow is the Y-tube sonar. It consists of three hydrophones covered by a flexible streamlined rubber "rat" that smooths the flow of water over the hydrophone, reducing ambient noise. The hydrophone wings are attached to a prominent U-shaped bracket that raised them above the deck, allowing a towing hawser to pass underneath.

The track of exhaust bubbles thins out behind the fired torpedo as the R-20 continues to follow.

Retrieving the Torpedo

At the time frame this photo was taken it was not unusual for submarines during torpedo training exercises to locate and retrieve their fired practice torpedo. That is what is happening here. The torpedo fired in the above sequence has now been picked up and hoisted onto deck and is being loaded back down into the submarine. Once back in port the torpedo will be pulled out of the submarine in a reverse of the procedure seen here, and it will be sent to a tender or shop ashore for refurbishment and reuse.

With his back to the camera is most likely a Chief Gunners Mate with a Torpedo rating. The rate of Torpedoman did not yet exist. On the right the other man looks to be an officer supervising the process.

The Chief on the left seems to be paying attention to something or somebody who is forward of the camera.

A block and tackle is attached to the rear of the torpedo and the front of the bridge. This is to control the rate of descent of the torpedo. These weapons were 21 inches in diameter and 16.3 or 16.7 feet long. They weighed between 2200 and 2400 pounds each. Careful control of this much weight was vitally important. Amazingly, note the complete lack of lifelines for the safety of the crew. The Chief on the left is dangerously close to going over the side. One wrong move by any of the loading crew and someone gets wet.

The view looking forward as the weapon is lowered into the torpedo room. The officer is forward watching the operation. No sign of the Chief. Note the control arrangement on the tail of the torpedo. The contra-rotating propellers were intended to counteract the rolling torque of the torpedo’s engine. Without them the weapon would continuously roll along its axis after firing making depth and course control impossible.

Just to the right of the man closest to the camera hip is the barrel of the 3"/23 caliber deck gun. The gun is in its housed position.

The Crew

Nine men and a Chief. This looks a lot like an inport duty section. This is approximately one third of the crew size for this vessel.

A "Duty Section" comprises enough men to be able to take the vessel to sea and be able to fight it, if necessary, for a limited amount of time. Each section would have enough men to man the important duties aboard. The good thing about submarines and the training the crew have is the ability to know each others jobs and be able to navigate and fight the ship as necessary.

Note the man who is 5th from the left is wearing unique boots. He is seen several times throughout in these photos.

This looks to be three officers on the bridge of the R-20. One is likely to be LCDR Alfred E. Montgomery, the Commanding Officer of the USS R-20. The names of other officers have not been located at this time.

This is a good view of the boat’s open-air bridge and periscope support shears. One officer is sitting between the two periscopes, and the third mast on the right is an extendable radio antenna mast. Just aft of the radio mast is a navigation light.

The wires connected to the angled brackets are mine and/or harbor defense net clearance wires. They can be seen more clearly in the photo below.

An officer on the bridge of the R-20. It could be LCDR Montgomery, the Commanding Officer. Another officer is to the right side of the bridge but only the top of his hat can be seen. An enlisted sailor works on something on the side of the fairwater and perhaps a Chief is on the aft fairwater deck.

This is a good view of the R-20’s conning tower fairwater, and the clearance wires can clearly be seen. The conning tower itself is a small vertical cylinder, just big enough for two to three men to stand upright, and it contained a periscope station for #1 scope. It also had four very small glass windows, called deadlights, and two of them can be seen just to the left of the sailor standing on deck. The conning tower is surrounded by a metal framework and plating called the fairwater, with the purpose of smoothing the flow of water around the tower, the periscopes, ventilation piping, and the bridge.

Looking at the bracing for the clearance wires you can see the "hooks" where the portable running lights were mounted. The red and green navigation lights were hung on these hooks and plugged into a water proof receptacle to supply them power.

In the background it looks like the Los Angles Lighthouse sitting on the end of that long breakwater.

Nice portrait of an R-20 sailor. He is an Electrician (Radio) 1st Class with two hashmarks meaning over eight years of service. This could be the photo album's owner. The man is married judging by the ring on his left hand.

The Deck Gun

This is a good photo of the business end of the 3"/23 caliber Mk 9 "disappearing" deck gun. This weapon had a vertically sliding breech block and used fixed ammunition (i.e. shell and propellant put together in a brass cartridge, similar to a rifle bullet).

The base of the mount had brackets that held ready-use rounds that could be immediately loaded and quickly fired upon surfacing. One round can be seen adjacent to the knees of the Sailor on the left. Additional ammo was stored below and would be brought up by crewmen formed into a passing train.

The end of the recoil cylinder can be seen just below and to the left of the barrel. The weapon was light weight and easy to use, and when retracted into its tub provided little underwater drag. However, it was a low powered weapon that fired shells with little punch. It didn’t have the power necessary to finish off targets quickly. There have also been reports of the gun having a nasty tendency to retract into its tub with the recoil of firing. This had obvious negative safety implications for the crew.

The following is part of a paper written bysSubmarine historian Jim Christley. This describes what a deck gun is and this gun in particular:

A deck gun type is defined by its bore diameter and bore length. Further refinement of the gun type is by the Mark and Modification number. The bore diameter is normally given in inches and the bore length is given in calibers. A caliber is one bore diameter. Thus, for a 3"/50 gun, the bore diameter, measured land to land is three inches. The length of the bore is 50 calibers or 150 inches. Each major type also was given a Mark number by the Bureau of Ordnance (BuOrd). A gun could have the same bore size and length and be a different Mark. When discussing the entire range of 3" guns in the Navy, it is useful to use the Mark number. For submarine guns only, is normally not necessary. Modifications to a particular Mark were also numbered. Thus, a gun was fully described with its bore diameter, bore length, Mark and Mod numbers.

The 3"/23 is the Navy’s early attempt at creating a dual-purpose gun. That is a single weapon that would be used both as an anti-surface and anti-aircraft gun. The diminutive 3”/23 Mark IX. It fired a projectile of about 13 pounds to a range of about 4.5 miles. Used in submarines it had no remote fire control system and was used in line of sight only. The mount was retractable in that the barrel assembly could be rotated to 90 degrees in elevation and the whole thing lowered into a containment cylinder. What appears as a splinter shield was the watertight cover that fitted snugly to the top of the containment. The gun’s drawbacks were that it had a fairly short range and it was prone to retracting when fired or at other inopportune times. Thus, one kept one's toes away from the containment rim.

The man second from the right is wearing the same boots as was noted in an above photo.

On the Pier

This photo was taken only a few minutes after the one above. Several R-20 crewmen are on the pier and seem to be interested in something going on behind the camera man. One man is in dress blues and the others seem to be in undress blues or working uniforms.

Looking Astern

View looking astern as the R-20 pulls away from harbor. Which harbor is not clear. It could be San Pedro (Los Angeles) or San Diego. An unidentified submarine is following behind.

The terminus for the clearance wires can be seen on the aft deck, along with an open top towing fairlead chock. There are also two other mooring line cleats attached to the edges of the deck. Their intended use is to secure mooring lines to the pier while in port.

View astern from the bridge with the underway colors flying in the breeze. There looks to be a signal halyard that has come loose.

Another stern view with a following submarine and another unidentified ship behind that.

After Deck

Sailors relaxing topside during the Maneuvering Watch inbound to port. The man sitting on the open engine room hatch and happily posing for the camera is wearing the same unique boots that has been seen several times above. By the ring on his left hand he is also a married man.

These boats had no air conditioning and poor ventilation and it tended to get very hot and stuffy below decks. Whenever it was possible, and when the Captain allowed, they would come topside for some relief from the conditions below.

Gun Sponson Addition

R-20 and two more R-boats in dry dock at Mare Island Navy Yard, California in March 1919, undergoing prep work for the homeport shift to Pearl Harbor.

The hull below the waterline has been scraped to prepare for painting. There also appears that work is in progress on the forward deck, where the 3"/23 caliber gun was removed. The deck structure where the gun was mounted and housed has been opened up to remove the "tub" that passed through the pressure hull. This hole was patched and a new wider deck installed to accommodate the new larger gun. This deck would later have supporting sponsons constructed under it.

The half cone shaped fairings on the forward superstructure are for the bow planes operating mechanism, smoothing the flow of water over them while submerged. The bow planes themselves are folded back against the superstructure in their retracted position.

Starting about midships down towards the bottom of the boat is the port side bilge keel. This device (there is one on the starboard side as well) is intended to reduce rolling on the surface that is caused by wave action.

Notice that the bracket for the Y-tube sonar is now mounted closer to the deck than in the above photos. The reason for this change is most likely related to water flow vibration that reduced the effectiveness of the hydrophones.

Upon completion of the work on June 17, 1919 the R-20 got underway for Pearl Harbor in company of her squadron mates.

Bow on shot with the boat sitting alongside a pier possibly at Mare island. The beginnings of an expanded sponson for the soon to be installed 3"/50 caliber gun can be seen just forward of the conning tower fairwater.

Hawaii ~ Pearl Harbor

Moored at the Naval Station Pearl Harbor, T.H. summer 1919. The main part of the Pearl Harbor Navy Yard can be seen in the background, with the prominent cantilever pontoon crane YD-25 clearly in view.

L to R are the submarines R-19, R-18, R-15, R-17, and R-20. Note that the expanded sponsons for the 3"/50 caliber gun have now been completed, but the gun and its mount have yet to be installed.

Similar photo as above but from a different angle. The R-19 and the R-20 have their torpedo handling masts set up and the R-20 has also rigged the boom. The boom for the R-19 is still laying on the deck. It seems the masts and booms offer opportunistic seating for off duty crews.