Vulcan Onshore Tip #13: Adaptation of McDermid Base

We do not recommend the use of McDermid base for any type of pile other than wood. But on occasion, contractors have found themselves in a position whom they have had to adapt a McDermid base to standard Driving Heads or Pipe Caps. The above shows the arrangement necessary to accomplish this.

Note: the McDermid Base was one of the first “customisations” applied to a Vulcan hammer. Vulcan licensed this from its inventor, Hugh McDermid. Although the conical cone on Vulcan bases was originally designed to mate with tapered wood pile heads, the McDermid Base gave better alignment. This is one of the few instances where a Vulcan hammer could drive the pile “directly,” i.e., without cushion material. Unfortunately hammers equipped with a McDermid Base could only drive wood piles, thus without adaptations such as this such a hammer was limited in its scope.

More information on McDermid bases and their application can be found here.

A Vulcan #2 equipped with a McDermid Base being set up for a demonstration driving to be included in an episode of the History Channel, 2005.

A section drawing of the #1 McDermid Base, from 1891. It also shows the lower rubber bumpers attached to the top of the base, along with the McDermid door and the bolt holding it in place.

The same diagram above in an earlier form, i.e., for a #1 Hammer dated 24 September 1941. Note that the diagram depicts the use of “wire rope” biscuits under the plug. These were fairly common when the diagram was drawn, but Vulcan soured on them during the offshore years.