The USS Holland propulsion system consisted of the following equipment:
A – 45 HP Otto Gasoline Engine
This was a water cooled, 2 cylinder, 4 cycle engine capable of developing 45 horsepower at 340 rpm. Fuel consumption was 1 pint per horsepower-hour.
The gasoline engine was a technological breakthrough. It was small enough to fit inside a submarine and powerful enough to drive the boat at 8 knots on the surface. The ability to develop 45 horse-power using an engine that was only 3 feet wide, 4 feet long and 5 feet high, was key to the success of the Holland VI.B – Friction Clutch
This clutch connected the engine to the intermediate shaft. It must have been a troublesome piece of equipment judging from the following entries in the ship's log:
|17 Aug 1900||Friction clutch on shaft carried away during charging|
|18 Aug 1900||Removed clutch, overhauled gear wheels and found OK|
|14 Sept 1900||Removed friction clutch|
|17 Sept 1900||Put in bronze clutch|
|30 July 1901||Bolt sheared off clutch, breaking connections in oil pipes and base of throttle|
|5 Nov 1901||Bolt in friction clutch carried away.|
These gears connected the engine (340 rpm) to the intermediate shaft (300 rpm). The gears were covered with a sheet metal case.D – Reduction Gear
These gears connected the electric motor/generator (900 rpm) to the intermediate shaft (300 rpm). The gears were covered with a sheet metal case.E – Clutch
This hand operated mechanical clutch connected the electric motor to the intermediate shaft.F – 50 HP Electro-Dynamic Dynamotor
This piece of machinery doubled as an electric motor for submerged propulsion and a generator for recharging the battery. The specification describes it as "Electric, waterproof type, 50 hp (nominal) with two communtators. Capable of developing 160 hp. 900 rpm." This motor was badly damaged when the USS Holland sank at the dock, and shorted out several times between 1900 and 1905 due to moisture in the insulation.G – Intermediate Shaft
This shaft was 4 inches in diameter and constructed of steel.H – Clutch
This hand operated mechanical clutch connected the intermediate shaft to the propeller shaft.J – Thrust Bearing
The thrust bearing transmited the thrust from the propeller to the hull of the shipK – Propeller Shaft
This shaft was 4 inches in diameter and constructed of steel.L – Shaft Seal
This mechanical device prevented water from entering the submarine around the propeller shaft.M – Stern Bearing
The stern bearing was larger than the other bearings to support the weight of the propeller. It was lined with lignum vitae due to its exposure to sea water (The internal bearings were babbited or bushed with bronze).N – Propeller
The original propeller was replaced by a larger experimental propeller in May 1898. This propeller was replaced by a smaller one (perhaps the original) in September 1898. According to the specification, the propeller was made of cast iron, 4' - 5" in diameter with a 2' - 9" pitch. It was left handed and turned at 300 rpm. A drawing of a 3 bladed cast iron propeller with a 4’- 6" diameter and 3’ – 2" pitch entitled "U.S.Submarine Torpedo Boat Holland - Wheel and Shaft of 50 ft Submarine Boat for J. P. Holland" was found in the National Archives.
The USS Holland did not have the ability to reverse the propeller when driven by the gasoline engine, consequently all maneuvering was done using the electric motor which could be reversed. On 9 January 1901, the armature burned out on a trip from the Naval Academy in Annapolis to the Norfolk Navy Yard. Lieutenant Caldwell completed the trip using the gasoline engine alone.
The primary modes of operation were:
Underway using the electric motor
The gasoline engine (clutch B) was disengaged and the other two clutches (E & H) were engaged. The USS Holland had a range of approximately 30 miles before the voltage in the battery dropped below prudent levels (severely draining the battery caused permanent damage to the plates in the cells).
Underway using the gasoline engine
The electric motor (clutch E) was disengaged and the other two clutches (B & H) were engaged. The 1050 gallon fuel tank provided a range of approximately 1000 miles on the surface).
Charging the battery
The propeller shaft (clutch H) was disengaged and the other two clutches (B & E) were engaged. The fact that the USS Holland could recharge her battery was a major advance in submarine design, however, the inability to recharge the battery while underway was severely limiting. Unfortunately, the necessary power to weight ratio was not available in 1896 when the engine was purchased. This problem was resolved in the "A" boats (built in 1901) which used a 4 cylinder 160 HP Otto engine for surface propulsion.
ÓCopyright 1999,2000,2001,2002 Gary McCue