The technology used was pretty typical for vibratory hammers of the era, including the large-pitch teeth gears bolted to cast steel eccentrics, 355 mm (14") throat width for American-style sheeting installation, Volvo hydraulic piston motors (for the high pressure units; vane style motors were used on the low pressure 1150,) and a clamp with an industrial style cylinder bolted on to push the movable jaw into the fixed jaw. Both jaws had two parallel sets of teeth with a gap in between to accomodate the interlocks on the sheet piles, which enabled the hammer to drive two sheets at a time.

Vulcan produced three sizes of medium frequency hammers, the 1150, 2300 and 4600. The size designated the eccentric moment of the hammer in inch-pounds. All of the hammers rotated at 1600 RPM.

Vulcan used the HPSI power pack for its vibratory hammer throughout the 1980's. (One of these is shown on the flatbed trailer in the 4600 photo below.) This power pack was simple and reliable, using air controls (as opposed to the electric controls used by competitors such as ICE and later APE.

Note: if you're looking for service and other technical information on Vulcan vibratory hammers, take a look at the Vulcanhammer.info Guide to Pile Driving Equipment.

Below: A Vulcan 4600 driving a caisson for Subsurface Contractors of St. Louis, MO. Driving caissons was and is a major application for vibratory hammers, a marriage from a construction point of view of driven piles and drilled shafts.

Above: the Vulcan 2300 vibratory hammer pulling sheet piling from a box cofferdam. In many ways the 2300 was the best of the three sizes Vulcan developed in its medium frequency line. The one drawback to the hammer's configuration was that its length to width ratio put its centre of gravity higher than many of its competitors, but its narrowness was great in tight places.

Above: the 2300L. This was an attempt to remedy the problem of high centre of gravity by using the same suspension and shear fender configuration as the high frequency 2800 hammer. Unfortunately the problems with the shear fenders experienced by the 2800 were replicated here, and the hammer was soon dropped from the line.

Below: One important innovation in this line took place in 1987, when Vulcan abandoned the clamp with a bolted-on cylinder (as shown in the 2300 photo above left) and went to a one-piece clamp with an integral cylinder. At 1350 lbs., the 7" model (used in the 1150 and 2300 hammers) was probably the lightest clamp of its kind, both then and now. It also eliminated many of the reliability problems of the separate cylinder. (The 7" refers to the large, piston diameter of the cylinder.)

Above: Vulcan 4600 driving H-beams. The hammer is using the Vulcan 10" clamp, the large counterpart to the 7" clamp. Watching the proceedings in the foreground is Mike Elliott of Pile Equipment, Vulcan's Florida dealer. Mike suggested that Vulcan produce a fixed and movable jaw set for the clamps whose two rows of teeth were further spread apart than the original Vulcan jaws to accomodate cold formed sheet piling, whose interlocks were physically larger than their hot rolled counterparts. Vulcan produced such pieces and christened them "Elliott Jaws."

Above: Rebuilding the 2300L case at PACO in Seattle, Washington, in 1991. The cylindrical roller bearings are being prepared for insertion in the case. Because of the continuously changing direction of the dynamic force, it is necessary to use an interference fit between the bore and the outer race. PACO's preferred method was to use dry ice to shrink the outer race and then lower it using a wire tied to the roller cage, a method Vulcan adopted for its own assembly.

The "A" Series Vibratories

In 1991 Vulcan introduced the "A" series of hammers (1150A, 2300A and 4600A) series of hammers. The biggest changes were a) the abandonment of the Morse shear fenders and b) the complete reconfiguration of the gear and eccentric design, inspired by information obtained from the Soviets. The first "A" series hammer was a 2300A, first used on a job by Agate Construction in New Jersey.

Vulcan also began to manufacture its own power packs, where it was able to make many technological advances.

Above: Vulcan 2300A power pack during assembly at Vulcan's Chattanooga facility. With its direct drive, variable displacement pump and electric controls, the power pack shown was a significant advance from its earlier power units.

Above: Vulcan 1150A hammer being tested at the Chattanooga facility. The larger, softer Morse shear fenders are gone, replaced by the Lord shear fenders used successfully on the MKT hammers. The 7" clamp was successfully carried over into this series. Note the use of a pipe motor guard instead of the "ICE" style motor guards on the 2300 and 4600. This feature, first used on the 1400, provided good protection for the motor, necessary as the hammer frequently swung during setting on a sheet or H-beam.

Above: the first Foster 4200 unit, manufactured by Vulcan. On each side of the suspension are bias weights, which are used to place additional static weight and assist driving.

Foster Units

One of Vulcan's more interesting ventures in the 1990's was the private label manufacture of a line of vibratory hammers for L.B. Foster in Pittsburgh. The first hammer to be produced was a replica of Foster's existing 1800 unit, but it became apparent that this unit was very expensive to produce. Vulcan then designed a line of medium frequency vibratory hammers, the 1050, 2100 and 4200 hammers. With the combination of Vulcan's and Foster's experience in vibratory hammer design and manufacture, this was the best line of medium-frequency vibratory hammers that Vulcan ever produced.

Above: Foster 4200 power pack during testing. The end-mounted control panel, with its neat layout, was an improvement over anything else that Vulcan had ever produced.

After the Acquisition

After it was acquired by Cari Capital, the company continued to support the line; however, it was left behind when Vulcan Foundation Equipment acquired the air/steam hammer line in 2001. It was ultimately sold at auction the following year.