In an effort to solve the problem of approaching a whale close enough to dart a harpoon into it, especially in the ice of the Arctic whale fisheries, it was thought that a harpoon fired from a gun would be the answer. There were may trials with a large swivel gun mounted in the bow of the whaleboat, but excessive recoil transmitted to the light-weight boat proved to be a problem. Therefore, a shoulder gun to fire a harpoon was tried. These harpoons had to be a light weight to reduce the recoil of the gun to a point where it could be endured by the man firing the gun. This proved to be a harpoon of approximately 3 lbs. `Some shoulder gun harpoons and bombs could only be used in one particular gun, such as the Robert Brown gun and harpoon. These are presented with the gun in which they were used (see the page for Shoulder Guns for these irons).
Bomb lances were introduced with shoulder guns to solve the problem of getting close enough to a whale to lance it, particularly in ice fields, and eliminate the often hazordous lancing operation. There were many bomb lances and the designs were slight variations on the basic design. Therefore only the most widely used bomb lances will be discussed. A complete list of patented bomb lances is given in the page on patents.
The shoulder gun harpoons and bombs presented here could be fired from any gun with a compatible bore. For the most part this was the Brand gun, which was made in three different bores. Some other guns could be used, such as the Grudchos and Eggers shoulder gun with a smooth bore.
The first successful shoulder gun was the Brand Gun, introduced by Oliver Allen of Norwich, Connecticut, in 1846. (See Shoulder Guns for a description of this gun). The gun fired either a bomb lance or a harpoon, both patented by Oliver Allen. The bomb lance was the first of its kind, patented in 1846 (U.S. Patent No. 4,764, Sept. 19, 1846). This bomb consisted of a two-edged cutting blade screwed into a brass bomb shell mounted on a long fuse tube. The rear part of the fuse tube was made of a hollow wood shaft to fit the bore of the muzzle-loaded gun, 7/8" bore. The fuse was ignited by the flash of the gun powder when the gun was discharged. This bomb lance was called the "Broomstick Lance" because of its long wood shaft. It had one major problem: it did not fly in a straight trajectory, but tended to hit the whale broadside, flipping end-over-end in flight.
Oliver Allen, of Norwich, Conn., also patented a shoulder-gun harpoon in 1848 (U.S. Patent No. 5949, Dec. 5, 1848). Allen's patent focussed on a method to improve accuracy in flight by minimizing the effect of the attached whaleline. He thought the point of attachmment of the line was most important, and it should not be attached by means of a sliding ring, as was the case for swivel gun harpoons, such as the Greener gun irons. He also felt the line should not be attached to the butt end of the iron to trail behind. In his patent specifications, Allen stated:
It is exceedingly difficult, if not absolutely impossible, to shoot a harpoon from a gun with accuracy when the line is appended to it by such a sliding swivel, or is attached to the rear of the instrument. It must be fastened at or near the middle of the harpoon, in order to have the harpoon advance in a straight or nearly straight course. This I have demonstrated after long experience and many experiments.
Oliver Allen's gun harpoon was constructed of a forward part, consisting of the head, shank and a socket, and a rear part which was a light-weight shaft to fit into the gun barrel. The socket was made of a short tube with a wide flat shoulder at its forward end, unlike the socket of a hand harpoon. The whaleline was tied around the shank in the usual manner, and rested against the wide shoulder of the socket. The rear part of the harpoon, which fit into the bore of the gun, was made lightweight because it served only to fit into the barrel for projecting the iron, and it contanined the fuse. It was not required to withstand the pull of the running whale.
There were three versions of this lightweight rear shaft. The earliest was the wood shaft; it was made in two longitudinal halves secured together by light line whipped around them, about 5" or 6" back from the forward end of the shaft. A metal ferrule was crimped around the butt end to prevent the wood from being shattered by the explosion in the gun barrel, and to further secure the two halves. A cork and leather button were screwed to the butt to act as a wad for a tight fit in the barrel. A second version resembled a + in cross section. Its butt end was made with a solid metal disk to act as the powder wad. The third version was a shaft simply made of thin wall iron tubing closed at the butt end with a plug.
The head configuration of the Allen
harpoon was first made 
as a two flue iron with a lance blade set
into a slot at the tip of the head, at a right angle to it, and
projecting partially beyond it. The blade may have been an attempt
to provide an aerodynamic stabilization fin because it could
serve no other practical purpose. The feature is not found on
hand-darted harpoons, but is found on other early gun harpoons,
around 1850, but only in the New London, Connecticut area.
Early Oliver
Allen gun harpoon head configuration.
The head configuration of the Oliver Allen gun harpoon was not a patented feature. The head was changed later to the more familiar four-flue design. This is the configuration depicted in the patent drawing. It was similar to two two-flue heads joined perpendicular to each other, with one projecting about 3/8" beyond the other - this was most likely to facilitate sharpening. This configuration has been referred to as a clover-leaf harpoon, and sometimes as the Orange iron.
