The Vulcan 560 hammer became the “#1 of Vulcan offshore hammers,” and the most popular of its offshore hammers from the 1970’s onward. Yet, although today the logic of a 5′ stroke hammer (especially when compared to the diesel hammers) is obvious, at the time it took a little persuading.
Vulcan had adhered to the “heavy stroke/low striking velocity” concept since the beginning, but by the early 1970’s the “race to the top” for hammer size–driven by the larger and deeper conventional platforms–was getting ahead of the barge capabilities of Vulcan’s largest customers. In the Gulf of Mexico that principally meant McDermott and Brown and Root, but also Santa Fe, Teledyne Movible Offshore and (a little later) Raymond. Basically when facing the need for a 300,000 ft-lb hammer, Vulcan’s “traditional” choice would be one like a 3100, which would weigh around 200,000 lbs. (100 US tons) plus cap and leaders. For many of the barges in the Gulf, that would necessitate the use of the main block to pick up the hammer and follow it as it drove the pile. The main block was okay for topsides and pile lifts, but in the constantly moving situation with a hammer, it was too slow.
A lighter hammer would allow the contractor to drop to the secondary block on the crane, the traditional block to use for hammers. This block could raise and lower the hammer faster, and give the crane operator more control over the hammer during both lift and operation. Vulcan “bit the bullet” and proposed the 560, which lowered the ram weight (and thus the frame weight) to around 30 US tons while preserving the striking energy with the 5′ stroke.
Vulcan presented the 560 to its customers, to mixed reviews. McDermott stuck with the 3′ stroke concept with the 3100. Its larger bench of barges–with the crane capacity to go with it–made the 3100 a more viable option for McDermott. But others–specifically Brown and Root–found the idea attractive, and B&R ordered the first 560 in early 1973. It was delivered later that year (a delivery which beat McDermott’s 3100 by almost two years!) and proved successful without too many “growing pains” such as were experienced with the 040 and 060.
Specifications are shown below.
Offshore Specifications for 010-340 Hammers
Offshore Specifications for 530-6300 Hammers
Some general arrangements–including later CAD ones from the 1990’s, showing the durability of the model–are shown below.
Some photographs of the hammer are shown here:
Making the final touches on the 560 hammer. The hammer is held together with cables and these are tensioned with a hydraulic tensioning device, which is being pressurised.
The ram of the 560 being machined. Compare this to the lathe work depicted on the 2 Yuan note used for this series’ logo. Vulcan routinely machined large pieces, so large that it was possible in some cases for the machinist to sit on top of the piece being machined.
The hammer assembled, it is laid on its side, secured to a shipping skid and in this case put on a truck for shipment.
Another view of Santa Fe’s Vulcan 560 at work. This wasn’t the ideal way to lean the hammer, but one of the things that make Vulcan hammers popular was their ability to perform when misused or mishandled.
A Vulcan 560 in Vulcan manufactured offshore leaders driving pile for the Korean contractor Daelim in 1991. Although Vulcan would have considered this an “onshore” job, it is a classic example of an offshore style hammer used to install a steel jacket. Note that the jacket is acting as the template, which in turn aligns and positions the piles. The leader and hammer assembly is lowered through the conical, adjustable stabbing bell and than the pile is threaded onto the pile cap, the assembly assuming the batter of the piles. The assembly is suspended from the hinged lifting bale at the top of the leaders. As the hammer drives the pile, the leaders are lowered to keep up with the hammer’s progress.
An overview of suspension cables, which became the accepted method of suspending Vulcan offshore hammers from the offshore type leaders. Onshore hammers used sheaves to raise and lower the hammer, but this was not applicable to a stub leader. Originally Vulcan intended for its customers to use the bar head (the bar is at the centre of the hammer on the 560 hammer on the left, between the two spelter sockets) and use a clip-secured wrap between the leader and the hammer. The suspension cables, attached in pairs to both hammer and leaders, proved a cleaner and more reliable method of doing this. In these photos spelter sockets are shown, but Vulcan furnished (when the customer needed them) swaged sockets. In either case the hammer was given sufficient leeway to ride down with the pile it was driving and give the crane operator the opportunity to keep the leader moving with the hammer without the cables becoming tight.
Another view of loading out a hammer package, this time being lifted off of the quay to be set on the deck of the ship.
Another offshore hammer moving onshore: the Korean contractor Daelim drives piles with a Vulcan 560 just off of the Korean coast in October 1991.
Vulcan offshore hammers could be found in places other than offshore. This 560 is installing pipe piles for a bridge in Juneau, Alaska in the late 1970’s. The major differences are a) the leaders and b) the mountain in the background.
A Vulcan 560 ram being machined by the Giddings and Lewis “floor” horizonal boring mill in 1993 (probably for Hyundai.) Boring mill capacity was the most important machining capability of the Chattanooga facility, as it was the hardest to procure elsewhere. Strolling down the aisle at the left is John Gourley, Vulcan’s last plant manager for the 2909 Riverside Drive facility. He combined an affable nature with a superb command over manufacturing processes and costs to be the best plant manager Vulcan ever had at the Chattanooga facility.
The first Vulcan 560 hammer, at the Chattanooga facility in 1973, with some of the employees. The 560 was Vulcan’s first 5′ stroke hammer; it was immensely successful and become the most important hammer in the Vulcan offshore line, and its introduction was a major step upward for Vulcan.
Vulcan 560 driving piles for a simple four-pile platform; Santa Fe was the contractor. This photo is interesting in several ways. It shows how the platform is used as a template. It also shows the batter of the piles; this was typical offshore. The operator is leaning the hammer properly so that the wear of the columns is more evenly distributed. Notice too the pile partially driven on the right; the flared pile head is due to premature refusal and brooming during driving, a testament to the punishment both hammer and pile experienced offshore.
The 560 became the “standard” for offshore hammers, not only for Vulcan’s American customers but for its foreign ones as well, such as Micoperi, ENAP, Petrobras, Hyundai, Daelim, Jardine and of course CNOOC, the sale to which of two (2) 560’s is documented here. It also found onshore use with such customers as Manson Construction.
The irony of Vulcan’s “gamble” with the 5′ stroke is that it turned out to be an advantage. All other things equal (especially the cushion stiffness,) for a given energy a lighter ram with a higher impact velocity will produce an impact pulse with a higher peak force and shorter duration. With steel piles, this is something of an advantage; their ability to withstand the higher stresses allows higher impact forces and stresses. With concrete piles, a heavier ram and lower impact velocity is favoured, as it results in lower compressive and tensile stresses during driving. The stage was set for more 5′ stroke hammers, and the 560 not only was the first to try the concept but was its most popular example offshore.