Engineering at Vulcan

Vulcan would have never endured as long as it did without a properly engineered product, especially in the punishing environment of impact pile driving equipment. There is a great deal of technical information on this site; here we give a glimpse as to how much of it came into being. There are special sections on CAD, Finite Element Analysis, and Numerical Analysis.

Vulcan’s reciprocating steam engines weren’t only used on pile driving rigs. In the same era Vulcan was also heavily involved in building dredges. We have a complete page on the subject; we’ll concentrate here on some of the design engineering aspects of those vessels.

From the beginning of the Warrington-Vulcan product line (and presumably earlier) until the 1950’s Vulcan drawings were largely drawn in India ink on linen. They were thus durable and reproduced well, and (as is evident here) have some artistic value. Unfortunately they were hard to change, but given the static quality of Vulcan’s product line that wasn’t as big of a disadvantage as one might think.

An example of Vulcan’s vertical integration: a pile hook, along with a shackle to go with it. Today components like this (especially the shackle) are usually purchased. On the right is a thoughtful “note to blacksmith.”

Towards the end of the 1950’s Vulcan made two important changes in the way it made drawings: it went to pencil drawings and it drew them on vellum, which was preprinted with standard borders and title blocks. Additionally, after the move to Chattanooga it mandated the use of lettering templates. All of these resulted in drawings that were easy to change and had a more uniform look about them, but did not have the visual appeal of their earlier counterparts. Also, the vellum tended to fray with repeated reproduction; Vulcan’s reproduction machines used a contact process with ammonia development, which made the office stink, especially with poor ventilation. This forced frequently used drawings to have to be redrawn frequently.

Computer Aided Design (CAD)

By the mid-1980’s CAD was becoming a viable option for companies the size of Vulcan. In 1986 Vulcan purchased its first personal computer (PC) for the purpose, but the original software was unworkable, so Vulcan purchased DesignCAD and began producing drawings by computer drafting. The first hammer to be principally designed by CAD was the Vulcan 1400 vibratory hammer.

Other examples of Vulcan’s CAD output can be found in our page on the “last hammers.

Finite Element Analysis (FEA)

While Vulcan’s competitors such as HBM trumpted their use of FEA for designing hammer components, Vulcan got its start in 1977 with the analysis of the 6250 pipe cap, which was being proposed to McDermott. The analyses were conducted by Dr. William Q. Gurley at the University of Tennessee at Chattanooga, who was later involved in this effort.

Vulcan went on to analyse the 6300 pipe cap when McDermott “upsized” the hammer. Vulcan also conducted analyses on other hammer size pipe caps and piston rods as well; the former led to lightening the pipe caps considerably.

Numerical Analysis

For most of its history Vulcan used “closed form” solutions to predict the cycle behaviour of its hammers. In the early 1980’s, however, Vulcan developed the capability to analyse a hammer cycle using numerical methods and flow prediction, including valve losses. The first hammer to use this type of analysis in the actual original design of the hammer was the Single-Compound Hammer, where the complexities of the flow made such an analysis almost mandatory.

The “indicator card” developed for the S/C hammer, using an HP-85 computer, 1982. The output was actually printed on thermal tape. The HP-85, with its Basic programming and VisiCalc spreadsheet, was a useful device for hammer design and trade union negotiations alike.

Vulcan’s most ambitious numerical analysis project was the ZWAVE wave equation program. That, in turn, was a prelude to projects beyond Vulcan, namely those of the closed form solution for the wave equation and the FEA solution of the wave equation, forward and inverse.


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