When whalemen refused to use poison harpoons, they sought another way to fasten to and kill the whale simultaneously. This remained a desired improvement, especially whaling in the ice fields of the northern fisheries. In place of poison, development of the harpoon turned to explosives.
Albert Moore Explosive harpoon
The first explosive hand-darted harpoon patented in the United States was invented by Albert Moore of Hampden, Maine in 1844 (U.S. Patent No. 3,490, March 16, 1844). His harpoon, fashioned after the single-flued harpoon, had a single barb that pivoted on an iron pin. When the barb was closed, in the darting position, a small wood pin was inserted through holes drilled through the head and shank. A cavity in the single barb opened to the rear, and accepted a small glass vial of explosive which was held in place by a wood peg across the opening. Moore described the action of his harpoon in the patent specifications:
As soon as the harpoon is thrown into the whale and fastened to it the wooden pin is broken by the power of the whale pulling upon the tow-line attached to the harpoon, and the fluke of said harpoon will open or turn upon the iron rivet, and in opening or turning upon said rivet will come in contact with the vial and break it, will produce friction, and cause the powder to explode, which will destroy the whale.
Albert Moore patent drawings.
Moore described the preparation of the explosive, but indicated that any suitable explosive could be used. There was no other fuse or other positive means to ignite the explosive. If the explosion were great enough to kill the whale, it certainly would have destroyed the harpoon. No examples of the Albert Moore harpoon have been found.
Charles Burt Explosive Harpoon Charles Burt Explosive Harpoon (tip missing). Length without tip is 36-3/4".
Another explosive harpoon was patented in 1851 by Charles Burt of Belfast, Maine (U.S. Patent No. 8,073, May 6, 1851). The explosive force was not intended to be so great as to kill the whale by its force, but rather to fire a projectile, the harpoon tip, into the whale like a bullet. The general appearance was similar to the single flue-irons. Nested under the flue was a trigger that depressed when the resistance of the blubber pressed on it when withdrawal forces were applied. The trigger actuated a firing mechanism in the head. A one-half inch diameter stud at the rear of the separable tip was inserted into a bore through the head acting as a gun barrel. A patch of linen made the stud a tight fit in the barrel to hold it in place until it was propelled by the explosive. During darting the single flue protected the trigger. A pull on the whale line caused the trigger to be depressed releasing the firing mechanism. According to the patent specifications, this caused the separable tip "...to be forced off by the explosion, in order to kill the whale immediately."
Charles Burt Explosive Harpoon Patent Drawings
Theodore Briggs Explosive Harpoon
Theodore Briggs of Philadelphia, Pennsylvania patented an explosive hand-darted harpoon in 1860 (U.S. Patent No. 30,869, Dec. 11, 1860). This iron was made with pivot barbs on the shank behind the explosive head. These barbs were to open outward to secure the whale after the head exploded to kill it. The head of the harpoon consisted of two metal tubes connected end to end by means of a threaded plug. The plug was made with a nipple for a percussion cap extending into the rear tube of the head; it also had a small hole through its length to transmit fire from the percussion cap to the forward tube. The forward tube was made with a solid, pointed tip for penetrating the whale during darting, and was filled with gunpowder. The assembled explosive head was not forged to the shank, but fit loosely over the end of it. The solid shank entered the hollow rear tube a short distance. A small wood shear pin held the head to the shank for darting; the end of the shank was thereby held a short distance back from the threaded plug with the percussion cap on it.
Pivot barbs were installed in a mortise through a widened section of the shank, and they pivoted on a single, common pin. The two pivot barbs were spring-loaded open by small leaf springs mounted to the shank. A sliding collarover the ends of the barbs held them in the darting position. The aft end of the shank terminated in a forged socket for mounting the iron to a wood pole, the same as standard hand-darted harpoons. In his patent specifications Briggs described the action of his harpoon:
Patent drawings for the Theodore Briggs explosive harpoon.
It is thrown by hand in the usual manner, so as to cause it to penetrate the skin and thick mass of blubber of the whale, and the tubular end then coming in contact with bone is suddenly arrested, while the momentum of the body and balance-shaft of the implement causes the breaking of the wooden pin ... and the consequent driving up of the stem end ... against the percussion-cap on the nipple ... exploding it and the powder ... thus destroying the life of the animal almost instantly.
During penetration the resistance of the blubber caused the sliding collar to move back to release the spring-loaded pivot barbs that would then open to secure the whale.
If the wood shear pin was weak, the initial impact against the side of the whale could have caused an explosion before penetration. If the shear pin was strong enough to to resist breaking during penetration, and the harpoon did not hit bone the mechanism would not function. It would be very unlikely that the harpooner could dart the iron to hit bone. The Briggs harpoon was never popular. No example of this explosive harpoon could be found.
Silas Barker Explosive Harpoon Silas Barker Explosive Harpoon. Length is 31-1/4", head is 3-3/4" long, 1" thick.
In 1865 Silas Barker of Hartford, Connecticut patented another explosive hand-darted harpoon (U.S. Patent No. 46,437, Feb. 21, 1865). This harpoon shot an explosive head farther into the whale before exploding. The hollow head was filled with gunpowder and sharp, angular pieces of steel to act as shrapnel. A long hollow tube filled with explosive was screwed into the rear of the head. This tube acted as a time fuse, igniting the powder in the head through a small hole at the forward end of the tube after the propelling charge had ignited that far. The tube fit into a corresponding hole that acted as a gun barrel in the stationary portion of the head which contained a firing mechanism.
The patent specifications describe a trigger wire extending from the hammer of the firing mechanism back along the shaft of the harpoon to a crosspiece. When the iron was darted, the resistance of the blubber on the crosspiece caused the wire to be drawn back, releasing the firing mechanism and igniting the explosive to propel the head farther into the whale. The crosspiece was described as a ring of thin metal positioned edgewise around the shank. The ring also attached to a "discharging-rod" that acted as a trigger, parallel to the shank. In the event that penetration was insufficient to allow the blubber to act on the crosspiece, a small line was provided by which the harpooner could actuate the mechanism manually. A large brass toggle barb acted to secure the whale after darting. The choice of brass may have been to prevent any spark that may have ignited the powder prematurely; otherwise brass was weaker than iron, and would have caused corrosion when in contact with iron. This toggle barb was farther back on the head so it would not have been damaged by the explosive. More of this detail can be seen on the patent model, and patent drawings, which differ somewhat from the actual iron that was produced. The Silas Barker explosive harpoon is vey rare; not many were made or used.
Silas Barker Patent Drawings (above) and patent Model (left).
Zeno Kelley Explosive Harpoon Author's interpretation of the Zeno Kelley Explosive Harpoon (no example found)
Zeno Kelley had a watch repair business in New Bedford, and repaired and adjusted chronometers for the whaleships. Whaling captains congregated in his shop to talk about whaling, and Zeno was very much involved in their business. In 1868 he was granted a patent for a hand-darted explosive harpoon (U.S. Patent No.78,673, June 9, 1868). The head of his harpoon was made hollow and filled with gunpowder. The iron was mounted on a standard iron pole and was hand darted. The mechanism that detonated the powder was the feature claimed in the patent. A percussion cap was placed on a nipple at the rear of the explosive head. The hammer to strike the cap was a metal rod forced against the cap by a coil spring. This mechanism was enclosed in a widened section of the harpoon shaft at the head. A pin placed through the rear of the hammer rod connected it to a sliding cover plate on the outside of the wide part of the shaft, over the firing mechanism. The plate was drawn back to cock the hammer. A pivot barb set in a mortise of the wide section acted to engage the hammer and hold it in the cocked position. When the pivot barb was in a streamlined darting position, and the sliding cover was drawn back, a small hole in the cover plate was aligned with a corresponding hole in the barb. A small metal pin inserted through these holes held the hammer in the cocked position. After the iron was darted and a force applied to the whale line, the rear tip of the barb caught in the flesh and caused the barb to open; this also pulled the metal pin through the hole in the cover plate and released the hammer to strike the percussion cap, and explode the head in the whale.
Zeno Kelley Explosive Harpoon Patent Drawings
In the patent Kelley stated that the harpoon could also be used as a gun harpoon, shooting it into a whale from a shoulder gun. For that, Kelley suggested mounting the iron on a short rod to fit a gun barrel, rather than an iron pole. To fasten the whaleline Kelley provided a cast iron slide that fit loosely around the harpoon shaft, forward of the socket. To minimize the recoil forces that could snap the whale line due to the sudden tension imparted to it when the iron first left the gun barrel, a coil spring was positioned around the shaft between the socket and the slide. This spring was to act as a shock absorber to lessen the sudden impact on the whale line. Kelley used this feature on an earlier gun harpoon patent, in 1867, for a non-explosive gun harpoon. This sliding collar and coil spring feature seems to be included here as a second thought.
Charles Freeman Explosive Harpoon Charles Freeman Explosive Harpoon (above) and Detail (below). Length is 41". Head is 4-3/4" long, 4" wide and 11/16" thick.
In 1872 Charles Freeman of Brewster, Massachusettes patented an explosive-head harpoon (U.S. Patent No. 126,388, May 7, 1872). In The Whale Fishery and Its Appliances, 1883, James Templeman Brown said this iron, charged with 3/4 lb. of gunpowder, was used for killing finback whales off the coast of Cape Cod in Massachusettes.
The cast iron head of the Freeman iron was hollow and filled with gunpowder. A time fuse with a short stem was attached to the rear of the head. A percussion cap was placed on a nipple at the rear of the stem which fit into a corresponding hole in the forward part of a widened shank section. This section was made to form a flat base on which the head was mounted. A screw through the toe of the base secured the explosive head to the harpoon. The widened shank also contained the firing mechanism. The hammer of the firing mechanism was a metal rod, forced against the percussion cap at the base of the head by a coil spring. A small spring-loaded latch held the hammer in the cocked position. A large iron pivot barb at the side of the shank, opposite the screw securing the head, acted as a trigger. During penetration the resistance of the blubber pushed the pivot barb in toward the shank. This action resulted in the barb pressing against the latch holding the hammer, causing it to release the firing mechanism and exploding the head.
Charles Freeman Harpoon Patent Drawings
On some examples of the Freeman iron a small safety lever was provided to prevent actuating the barb inadvertantly. Most Freeman irons were made with two small stationary barbs brazed or forge welded to the shank to make withdrawal more difficult, preventing the iron from working its way out. However, there are some examples of the Freeman iron which do not have these small shank barbs.
There were several Freeman irons made, but they were never very popular, probably because the explosion would have destroyed the harpoon and its barb, and possibly would have blown the iron back out of the whale.
©: 2000 - 2008Thomas G. Lytle . All rights reserved
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