Continuation of:
English translation of the French typescript,
La traversée de l’ Atlantique par les Chasseurs de Sous Marins contruits en Amérique.
Translation by Marc Terraillon. Copy editing by Todd Woofenden


Studies and Planning for Construction of Subchasers


The American conception of the fight against the submarines

April 6th, 1917

From their declaration of war against the Central Empires on 6 April 1917, the United States envisaged the immediate sending of ships to Europe to cooperate with the Allies in the submarine fight.

But if the US Navy readily accepted the principle of this common action, it criticized the methods followed by our General Staff.

"The Navy department, all officers with whom I had the opportunity to converse," writes our naval attaché in USA [1] "have the fixed idea that the war against the submarines is not conducted correctly…

[1] Capitaine de Frégate de Blanpré – 18 May 1917 (At.N to M.P)

We want to help you, said (US) Admiral Benson to (French) Admiral Chocheprat, we will send you destroyers, patrol boats, submarine chasers, submarines if you want, but we want to know if you have a plan for their use.

We disarm ourselves thus, to the detriment of our own defenses, and we are ready to sacrifice ships, but we want you to act, to study an offensive plan, and not to limit your effort to try to protect the merchant marine more or less effectively." [see note 1 below]

Convinced by this idea, the Navy Department had ordered the building of 350 submarine chasers of the 110' type, early in April.


The Choice of US submarine chaser type

 The first submarine chasers built in America before 1917 were small wooden ships of 80’, or “Canadian speedboats,” [see note 2 below] of which the British Government ordered more than 500, and from which France bought a few models. The hulls came from Canadian builders and the engines from Standard Motor Construction Company, Jersey City (U.S.).

The American government, by adopting the 110 foot submarine chaser (33 meters), wanted to achieve the following objectives:

1. Build ships bigger than those of 80 feet, whose dimensions had been recognized as insufficient to navigate in open sea and to attack submarines effectively.

2. Provide these subchasers of a type engine that had been tested and could be manufactured quickly in large numbers.

3. Build hulls very quickly, which required the use of the wood since it was easier to obtain than steel and a workforce could be recruited easily across the country.

Driven by the goal of obtaining chasers quickly, the Americans adopted the Standard Motor Company 220 hp engine, already in use in the Canadian speedboats; but to increase the power they had to resort to three engines instead of two. [see note 3 below]

The main characteristics of this submarine chasers (or S.C.) were:

Tons: 74 tons

Longitudinal section: 33 meters (metric length between perpendiculars)

Midship section: 4.22 meters (metric hull beam)

Draft: 1.50 meters; back draft: 1.80 meters

7 waterproof compartments, separated by 6 full sheet iron partitions (except the third, with a waterproof door)

Engine: 3 gas engines of 6 cylinders (255 x 275) – 220 hp each
1 auxiliary engine with a dynamo
A compressor (compressed air) and a petrol / gasoline pump
3 screws (only the central screw can be disconnected)

Radio equipment: 1 radio (power = ½ kilowatt). Range varying between 150 and 200 nautical miles

2 guns of 57 mm. (55 rounds by gun)
4 machine guns
2 depth charges

1 anchor of 200 kgs
2 chain cables of 14 meters
1 anchor of 60 kgs
1 windlass

Boat: One dinghy

Petrol / gasoline capacity: 9800 liters

Presumed range: 1500 nautical miles at 12 knots

Designed maximum speed: 18 knots

Crew (for transatlantic service):
2 officers.
2 non-commissioned officers and 10 sailors.
2 non-commissioned officers and 4 machinists.
a total of 20 men


The trials of SC 6
6 July 1917

Of the 350 planned submarine chasers, the shipyard at Brooklyn (Navy Yard) had to build 60.

The first completed was SC 6, which performed its trials on the Hudson River on 5 July, less than three months after the launch date.

The results were as follows:

1. Engine and speed trials, distance one mile:
3 engines - maximum speed - 15 knots at 450 rpm
2 engines (side), central engine disconnected - maximum speed - 14 knots
Central engine only - maximum speed - 8.86 knots

2. Consumption and endurance trials :
15 knots - consumption - 350 liters per hour
12 knots - consumption - 115 liters per hour

The operation of the engines was satisfactory, but the maximum speed obtained was lower than expected. We attributed this difference to the poor performance of the propellers. The engines proved resilient and were easy to drive, however oil vapors in the engine compartment bothered the crewmen.

The range at 12 knots, instead of the expected 1,500 miles, was calculated at 1,030 miles maximum. (Note 1 - see the report of the chief engineer Trisqueneaux, in charge of evaluating the subchasers sold to France.)

Search for a new type of subchaser

10 August 1917
(At.N at M.P.)

The results obtained with the first delivered subchasers were judged insufficient by America and France. Information was available on the possible decision by the Navy Department to stop the production of new subchasers and to build only destroyers. In reality, this information was incorrect and our Naval Attaché summed up the American position:

"It is certain that there would be interest in building a model subchaser that is larger than the current 100 feet, but we had great difficulties in finding powerful engines to provide a sufficient speed for these ships. We have installed 3 engines of the most powerful type. Could we maintain that speed with larger vessels?

The shipyards also believe that if we adopt a longer vessel, it should be built of steel and consequently would be built by shipyards different from those who have received orders for the 110' subchasers. However, the shipyards that build destroyers are already overloaded.

Meanwhile, we will experiment at three shipyards with the following types of ship:
1. A steam-powered 110' subchaser
2. A steam-powered 135' subchaser (wood)
3. A 135’ subchaser with gasoline engine (steel)

So, in few weeks, the U.S. Navy expects to be in possession of interesting data for comparison and, maybe, will adopt a new type of subchaser in the future.”

At this time, the French General Staff, willing to buy 50 new vessels, met with its delegates in the USA, with the information on the projects of U.S. manufacturers. But the Navy Department was skeptical about the success of this research and considered abandoning the construction of subchasers. However, in November, the Foundation Company, which was founded shortly before the war, submitted a draft of a ship to our Naval Attaché.


Proposals of the Foundation Company

5 December 1917
Report of the Study Commission

A commission of French officers was responsible for reviewing these proposals. The commission submitted to the Naval Attaché the following report:

“The current submarine chasers (110') have the inconvenience, in spite their 3 engines, of having a relatively slow speed, even less than that of some German submarines on the surface. The dimensions, although larger than speedboats, are still too small to properly navigate on the seas and to carry guns sufficient to effectively combat the German submarines. The French Navy, awaiting delivery of a number of 110 foot ships was, from the beginning, aware of these defects and inquired about the possibility of higher speed ships.

This is the origin of the proposals of the Foundation Company.

This company introduced, at first, a draft of a steel vessel of 140 feet, with 2 coal-fired boilers and 2 steam engines, with a total power of 1200 HP.

Maximum speed: 18 knots
Range: 2,000 miles at 12 knots

The commission believes that the Foundation Company is too new and that the difficulties of labor would be such than delivery times and quality would suffer.

On the other hand, the Navy Department had a project of larger submarine chasers, and had the intention to build 1000. It would be highly desirable to consider a joint study about new submarine chasers, whose need is recognized by the French and U.S. Navies.

Also, Captain Robinson of the Listening School in New London said of the submarine chaser, unless it is very large and becomes a real destroyer, it must have the main functions of detecting the presence of submarines and locating them if possible, with armament consisting of depth charges and machine guns.

Since the current headphones are sensitive to all noises, submarine chasers must have no engine noise when they are stopped, and therefore the steam engine is eliminated.

Finally, since a gasoline engine does not allow the boat to attain a speed greater than the speed of the submarine chaser of 110 feet, a diesel engine must be chosen.

The diesel engine (4 strokes - 700 HP) would be good, but very few companies are able to build them, and they cannot currently take orders.

4 December 1917
(At.N at M.P.)

By submitting its report to the Minister, the (French) Naval Attaché rightly said: "In the uncertainty of the situation, it seems more appropriate to stick to existing types of submarine chasers, if you conclude that they can be used in the submarine war,” and this conclusion was adopted by the General Staff.


The Ford subchasers [see note 4 below]

23 January 1918
(At.N at M.P.)

The issue of construction of submarine chasers would suddenly change in January 1918, as shown in the following letter from the Naval Attaché to the Minister:

“Less than three weeks ago,” he writes, “Admiral Benson (Chief of General Staff of the U.S. Navy) after his return from France, had stated categorically that the American Navy shouldn't build new submarine chasers. The U.S. Navy intends to devote all of its resources in military and private shipyards in the construction of destroyers.

It is true that many US Navy officers felt that a subchaser with dimensions greater than 110 feet would be a good solution; this idea was spread by the specialists of submarine detection.

The Navy Department had studied a 200' subchaser, but could not find anyone to build it, either because this new type of ship was daunting for builders, or because it was not possible to engage in the construction of a large number of these units without impeding the destroyer program.

The large majority of the U.S. Navy officers, including Admiral Benson, wanted destroyers, and a minority of officers wanted to build a large subchaser, but they were stopped by the inability to realize this ship.”

This is when Mr. Ford appeared, whose name seems to be magic. He took up the position of the destroyer supporters. Admiral Benson, whose rapid change of position surprised me, told me that he continued to be opposed to the construction of these ships, but on the demand of the Secretary of the Navy, he had agreed to build 100 of these vessels.

The main features are:

Displacement: 500 Tx
Construction: Steel
Length: 60.95 meters
Width: 7.77 meters
Draft: 2.21 meters

A 100 mm gun forward
A 75 mm anti-aircraft gun aft
Maybe two 520 mm torpedo tubes (twin)

Oil boilers (steam turbine or steam engine)
One propeller
Speed : between 16 and 18 knots.

The question of delivery is the most troubling. Mr. Ford promises delivery of the first ship five months after signing the contract, 10 for the sixth month, 20 for the seventh, 25 for the eighth and following months.

The technicians say that this program is unworkable, and the first ship will be 2 or 3 months late. A significant production will not be possible until the early months of 1919. Then the production will certainly be very fast. Editor's Notes:

1. Adm. Benson's remarks as captured here are fully consistent with the U.S. position: There was a clear, deliberate effort in developing the subchaser force to wage an offensive against submarines, and not to use the boats for other purposes.

2. "Canadian Speedboats" refers to ML boats built at Elco in New Jersey and assembled in Canada. Prior to the declaration of war by the U.S., a U.S.-based boatbuilder supplying Allied forces with war boats would have been untoward. In this case, Elco shipped components to Canada. They were then assembled in Canada, and shipped from Canada to England.

3. There are several sources that praise the Standard Motor Construction Company engines as highly reliable, capable of withstanding heavy seas, etc. But this more practical account -- that they were already being used, had a history, and could be manufactured quickly in large numbers -- is more than likely correct. I would propose that availability of these engines was the main reason for their selection; and that their track record was adequate to justify the selection, given the constraints of the project.

4. The Ford chasers refers to the Eagle boats built by Ford.