Vulcan Drop Hammers

Bulletin-67A-Drop-Hammer-Diagram
Vulcan drop hammer, shown with the Casgrain style wood block for a hammer cushion. Note the wooden leaders, which were common for drop and air/steam hammers alike until the 1950’s. The Casgrain wood cushion “D” was a teardrop shaped piece of wood (usually oak) which projected out of the top of the driving accessory. An iron band (usually Norway iron) went around the circumference of the top of the block to retard brooming of the cushion material. The Casgrain configuration was also used with the steam hammers in the early years, the band interfacing with the base cone. This eventually yielded to the conical cones with receptacle for cushion material that have characterised Vulcan hammers since.

Although Vulcan is best known for its air/steam hammers, out of necessity as much as anything Vulcan produced a line of drop hammers for most of its history.

Until the advent of “automatic” hammers such as the Warrington-Vulcan hammers, drop hammers were the only way driven piles were installed. Drop hammers were (and still are) the most practical way for small quantities and short lengths of piles to be driven. Vulcan not only produced the drop hammers and driving accessories, but until World War II produced an extensive line of rigs to run them in.

One major disadvantage of the drop hammer was the relationship between the stroke and the ram weight. The light ram and long stroke of many drop hammers made them prone to pile damage, as this testimonial illustrates.

Blaw-Knox-Drop-Hammer
From the most “retro” part of the product line, the shape of things to come: a large (57,260 lb.) drop hammer with its 24,100 lb. pipe cap for driving 72″ pipe piles at the Blaw-Knox foundry in East Chicago, IN. The photo dates from around 1950. Between the hammer and the cap is a Blaw-Knox official, Water Daspit, Vulcan’s treasurer, and Campbell V. “Doc” Adams, Vulcan’s chief engineer. An Australian immigrant, his initials first appeared on a drawing in 1912; his last regular production hammer was the offshore 060 in the late 1960’s. His designs dominated Vulcan’s product line for much of the twentieth century. With this drop hammer, Vulcan’s product line had outgrown its production facility, a problem the company would face once again during the offshore years of the 1960’s and 1970’s. Blaw-Knox would, in fact, play a role there too, manufacturing most of the Vulcan 5150 and 6300 hammers for Vulcan.

2186
A drawing of the cap. Note that the cap is hollowed out, to save weight. These voids are formed by sand “cores” which are placed inside of the main sand mould for the casting. They were common in large Vulcan caps until the late 1960’s, when problems with core “burn-in” (where the sand would be melted and fused into a solid during casting) forced Vulcan to abandon hollowing out its caps. The cushion configuration is also shown, which is very similar to that used in Vulcan’s air/steam hammers.

Bulletin-66G-CoverBy the time Vulcan moved its headquarters to Florida in 1964, Vulcan’s drop hammer production had dwindled, victim to the success of its air/steam hammers (and other automatic competitors) and the fact that smaller facilities could produce the hammers more cheaply. Nevertheless Vulcan continued to offer the drop hammers in its line. At the right is the cover for the last bulletin (66-G) advertising the drop hammers, issued late in 1965. You can download a copy of that bulletin by clicking here or on the bulletin cover to the right.

In February 1974 Vulcan discontinued production of the conventional drop hammers.  The last drop type hammers the company produced, however, were hairpin hammers, which are simple pieces of plate with a slot in them for alignment. They are generally used with sheet piling; they are self-aligning and do not require leaders. As was the case with the earlier drop hammers, Vulcan found it nearly impossible to compete with “homemade” hairpin hammers that contractors manufactured for their own use.

Vulcan drop hammers are an interesting sidebar in the history of a company whose main product line contributed greatly to their marginalisation as the mainstay of pile driving equipment.

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