The fourth in our series on the ads which Pile Buck allowed vulcanhammer.net to run was this shot of a Link Belt 520 driving shell piles using the Vulcan Expanding Mandrel. The mandrel’s history and shell piles in general are discussed here.
The Link Belt 520 is an interesting story in itself. The diesel hammer was first developed in Germany by Delmag. After World War II, the technology was seized as Alien Property and licensed to the Syntron concern. They made two key changes to the diesel hammers. The first was to use a true atomizing injection of the fuel (as opposed to the splash system common to most diesel hammers then and now) like a conventional diesel engine. The second was to put a “bounce” chamber on top, basically a compressed air chamber to store energy on the upstroke, which was then put back into the ram during the downstroke. This increased the blow rate and shortened the stroke.
The benefits of atomized injection were and are not clear; in some cases the Link Belt hammers were found to stop the ram before it struck the anvil, thus the hammer never impacted! The bounce chamber mystified many engineers and inspectors in the day, but the concept was adopted by IHC for their hydraulic hammers in the 1980’s.
The Syntron hammer was sold to the crane manufacturer Link Belt, who in turn sold it to International Construction Equipment in the late 1970’s. They still manufacture diesel hammers but they have changed the concept of the hammer somewhat since then.