Brennan torpedo
First practical guided missile, patented in 1877.
The Brennan torpedo, patented in 1877 by Louis Brennan, an Irish-born Australian inventor, used two contra-rotating propellers. These propellers were spun by wires rapidly pulled from drums inside the torpedo. By varying the speed of the wires connected to a shore station, an operator could guide the weapon to a target up to 2,000 yards (1,800 m) away at speeds reaching 27 knots (31 mph). While earlier guided torpedoes had been invented by John Ericsson, John Louis Lay, and Victor von Scheliha, Brennan’s version was much simpler in concept and worked effectively over a useful range at a satisfactory speed, making it arguably the first practical guided missile.
The torpedo’s appearance resembled later models, except for a flattened oval cross-section instead of a circular one. It ran at a consistent depth of 12 feet (3.7 m) and had an indicator mast that just broke the water’s surface; at night, a small light on the mast was visible only from behind. Inside, two steel drums were mounted one behind the other, each holding thousands of yards of high-tensile steel wire. The drums connected through a differential gear to the twin contra-rotating propellers. If one drum rotated faster than the other, the rudder was activated. The wires’ other ends were attached to steam-powered winding engines, whose speeds could be finely adjusted for sensitive steering control.
Using wire 0.04 inches (1.0 mm) in diameter, the torpedo reached 20 knots (23 mph); later, thicker wire of 0.07 inches (1.8 mm) boosted speed to 27 knots (31 mph). Elevators controlled by a depth-keeping mechanism, along with fore and aft rudders operated by the differential between the drums, guided the weapon. The operator stood on a 40-foot (12 m) telescopic steel tower, extended hydraulically, and used special binoculars with controls to electrically adjust the relative speeds of the twin winding engines. This allowed him to follow the torpedo’s track and steer it accurately. In Admiralty tests, an operator hit a floating object at 2,000 yards (1,800 m) and could turn the torpedo 180 degrees to strike a target from the opposite side.
According to Tomlinson, in 1874 Brennan watched a planing machine driven by a belt and realized the paradox that a machine could move forward by being pulled backward. Beanse adds that Brennan noted the driving side of the belt was taut while the non-driving side was s
- patented
- 1877
- inventor
- Louis Brennan
- nationality
- Irish-born Australian
- field
- Military ordnance
- known_for
- First practical guided missile
- range
- Up to 2,000 yards (1,800 m)
- speed
- Up to 27 knots (31 mph)
Lore & Background
Louis Brennan, an Irish-born Australian inventor, patented the Brennan torpedo in 1877. The torpedo was propelled by two contra-rotating propellers spun by pulling wires from drums inside the torpedo. Differential speed on the wires connected to a shore station allowed guidance to a target. The torpedo ran at a consistent depth of 12 feet and had an indicator mast that broke the water's surface. The operator, positioned on a 40-foot telescopic tower, used binoculars with controls to steer the torpedo electrically. In tests, an operator could hit a floating object at 2,000 yards and turn the torpedo 180 degrees.
Reader's Guide
The Brennan torpedo represents a significant step in the evolution of guided weapons. While earlier guided torpedoes existed, Brennan's design was simpler and worked over an acceptable range at a satisfactory speed, leading to its adoption as a standard harbour defence throughout the British Empire for over 15 years. The torpedo was used in installations at Cliffe Fort, Fort Albert, Plymouth, Cork Harbour, Hong Kong, and Malta. Its manufacture ended in 1906 after a committee recommended removal due to short range and night-launching difficulties. The Brennan torpedo's legacy lies in demonstrating the practical feasibility of remote guidance for naval weapons, paving the way for later guided missile systems.
Did You Know?
- The Brennan torpedo was propelled by pulling wires from drums inside the torpedo, not by an onboard engine.
- The operator steered the torpedo using binoculars with controls that electrically varied the speeds of twin winding engines on shore.
- In tests, the torpedo could turn 180 degrees to hit a target from the off side.
- The Brennan torpedo was used for harbour defence in the British Empire for more than 15 years.
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