Welcome to vulcanhammer.info, the site about Vulcan Iron Works, which manufactured the durable air/steam line of pile driving equipment for more than a century. Many of its products are still in service today, providing reliable performance all over the world. There’s a lot here, use the search box below if you’re having trouble finding something. Also look at the end of an article, there are helpful links to more information with every post.
Vulcan frequently produced an ad for the Offshore Technology Conference. Probably the best one was the “Stamp Ad.” The “stamp of quality” theme had appeared in Vulcan’s literature for many years before that, but Vulcan’s graphic artist Carol Carr took it to a new level with this one in the early 1970’s. It was unusual in many respects; it was in colour (colour wouldn’t become standard in Vulcan literature until late in the decade) and it was an 11″ x 17″ fold-out.
Snippets of Carol’s artwork have been on this site since its beginning in 2007, such as the masthead below:
Vulcan hammers appear often in geotechnical engineering textbooks and other reference material. It’s rare that it would happen outside of that discipline, but happen it did.
In 1960 the first edition of Mechanics of Materials by Archie Higdon, Edward H Ohlsen and William B. Stiles was published with the 1200A extractor photo shown above. The purpose of including it was to illustrate concentric axial stresses through the connecting links on the side from point A to point B, and specifically through the plane c-c. Vulcan granted permission to use the photo the year it left Chicago and moved to Chattanooga.
Evidently the illustration “made an impact;” it was retained through the Fourth Edition in 1985, by which time they had picked up two additional authors, John A. Weese and William F. Riley. It was in the Second Edition when this webmaster discovered it while taking Mechanics of Materials at Texas A&M in the mid-1970’s.
The indicator card, and the devices that produced them, have been around about as long as there have been steam engines. The basic idea is simple: as the piston of the engine moved, a pressure indicator moved a needle and pen up and down on a paper (usually a rotating drum) and produced what’s called in thermodynamics a pV diagram, shown below.
The steam engine (or any reciprocating engine, they’re also used with internal combustion engines as well) is somewhat straightforward in that it has a fixed stroke. With an impact pile hammer, you have a free piston engine whose stroke is not determined by the rotation of the crankshaft. Vulcan’s attempt to attach an indicator mechanism to its smallest hammer (the DGH-100,) shown above, is a little tricky. The telltale rod coming out the top of the ram moves the pen radially around the drum through a lever and cord mechanism. The pressure from the hammer moves the pen up and down on the drum. Either the pressure above the piston or below can be fed to the indicator mechanism, as shown below.
Whether Vulcan actually did this is unknown. Vulcan used a more modern approach to determine pressure-time and pressure-displacement histories in its linear vibrator, and the analysis software Vulcan developed electronically generated indicator cards for its single-compound hammer.
Mechanical indicator mechanisms are still used for slower, reciprocating engines (usually steam) but no matter how they’re made, indicator cards–and the concept behind them–are important in the performance analysis of reciprocating engines of all kinds.
As was the case with its 65C, Raymond made multiple improvements to the Vulcan 80C hammer, but used a slightly different approach.
Probably because the patents on the Super-Vulcan hammers hadn’t run when Raymond saw the need to modify the Vulcan hammers, Raymond started by extensive modifications on the Vulcan 80C, which are similar to those they made later on the 65C. The result is the hammer shown above. There is no doubt that Raymond probably had as much money in the modifications–or more–than the original hammers, but as Charlie Guild observed to me, Raymond had “no idea” what their costs were.
That may not have been a problem. For one thing, Raymond’s superintendents had a reputation of being hard on the equipment; it was cheaper, in their view, to damage the equipment rather than to stop the job. Raymond’s equipment designers responded to this by making these hammers more rugged than the original Vulcan hammers, and that’s saying quite a bit.
Probably the modification that gave the best return on the investment was the conversion from column keys to cables, one that Vulcan eventually did on its hammers. With the 80C, it was faced with the same problem as Vulcan: how to deal with the steam belt, which got in the way of running the cables straight out of the columns. Vulcan’s solution is discussed here; Raymond opted to shift the cables slightly off column centre, using eccentric and concentric column sleeves. The result, coupled with running the cables to the head, worked well, especially with the Raymond Step-Taper piles, which were probably the most grueling test of a pile hammer ever devised for onshore piles.
It’s noteworthy that Pile Hammer Equipment, in its approach, “dog-legs” the cables a bit as they go to the head while keeping them concentric with the column, thus avoiding the steam belt.
Raymond went on to develop a “true” Raymond 80C as it had done with the 65C, but at this point documentation lacks for this hammer.
Specifications for Raymond’s 80C and other air/steam differential hammers are below.
Without a doubt, one of the most interesting photos Vulcan had in its collection was this one, taken of a Vulcan #0 driving reinforced concrete sheet piles 500 mm x 600 mm x 21.9 m long (20″ x 24″ x 72′) for the New Harbor Wall in Havana, Cuba. The piles are being driven off of the Cristóbal Colon floating derrick, owned and operated by the contractor, Arellano y Mendoza. The photo is dated 1927.
An interesting example of late Soviet commercial art (no, that’s not an oxymoron) is this one, the cover to the literature for the SP-88 concrete pile cutter, from 1989. The array of cubes on the cover represents square concrete piles; the one in the lower left hand corner has been cut. An interesting graphic presentation.
It’s evident that Vulcan had some difficulty in getting the right combination of economy, operating pressure and configuration with its 65C and 65CA hammers. Did Raymond, which made many of its own designs of Vulcan style hammers, do any better?
Based on its experience with the Vulcan differential hammers, Raymond designed several differential-acting hammers, including its own 80C, the 150C, and this hammer. A general frontal view is shown at the right; a photo of one in Vulcan’s yard is above. Raymond made several interesting changes in the hammer design:
Different sheave had design.
Raymond configured the hammer for 120 psi operating pressure, which was one of Vulcan’s original proposals (the Raymond probably antedates the Vulcan 65C.)
Coil springs (later rubber springs) at the top for the hammer extension, or sled, which Raymond always used with its leaders.
Male jaws to mate the hammer with the extension (Vulcan later used male jaws for its offshore hammers.)
Cables from head to base. Raymond used a tapered bottom fitting; machining the mating tapered holes in the base was tricky and expensive, as Vulcan found out the hard way when it machined a base for the single-acting Raymond 1-S.
Draw bar for the slide bar instead of the hammered keys.
Baffle in the cylinder for the exhaust; the ports for exhaust were probably higher than for any other Raymond or Vulcan hammer.
Steam chest bushing, which Vulcan adapted and improved upon as a removable liner.
Lighter, dished-out pistons for the piston rod. (Why weight reduction was necessary for a striking part component isn’t quite clear…)
Vulcan acquired a great deal of Raymond engineering and inventory when Raymond finally fell apart in the early 1990’s, and was in the process of incorporating many of Raymond’s changes in its own product line when the company was merged in 1996.
Specifications for the Raymond 65C are shown below.
Here we link to the operations manual (or “Certificate” as the Russians referred to it.) We trust that you will find this informative as to the operation of this concrete pile cutter, which (to our knowledge) has not been duplicated elsewhere.
Yu. V. Dmitrevich, VNIIstroidormash L.V. Erofeev, Stroifundamentservice V.A. Nifontov, Stroifundamentservice D.C. Warrington, Vulcan Iron Works Inc.
This article was originally published in 1993 or 1994. The graphic above shows a 9 kJ unit mounted on an excavator.
Hydraulic demolition hammers mounted on hydraulically powered excavators are becoming increasingly widespread in world practice. They allow the excavators to be used for breaking rock and permafrost, break up large rocks, old foundations and reinforced concrete structures, and other jobs.
Outline of the Machine
Hydraulic demolition hammers are often equipped with hydraulic accumulators in the pressure line and sometimes in the drain line as well (as is the case with the Raymond hydraulic pile driving hammers) to achieve higher efficiency and to smooth pulses of fluid pressure in the hydraulics. Compressed nitrogen is mostly use as the elastic element in these accumulators.
The proposed hydraulic hammers differ from similar machines of leading companies outside of Russia such as Krupp of Germany, Montaber of France, and NTK in Japan. The main difference is in the accumulators the Russian machines have no compressed nitrogen accumulators, but are equipped with hydraulic accumulators having a so-called “liquid spring,” which is a closed volume of hydraulic oil compressed under pressure four or five times the pressure in the hydraulic system. Possible leaks from the inside of the hydraulic spring are compensated automatically when the hammer is switched off. Such a hydraulic accumulator does not need any adjustments and control during operation and its parts can serve as long as the hammer itself.
The main reason this design was chosen relates to the conditions in Russia itself. The temperature gets very cold, down to -60° C under these conditions the rubber in the bladder type gas accumulators will become embrittled in the temperatures common in many parts of Russia. Once this has happened, the bladders will burst and the machine will have to be completely disassembled and the bladder replaced. This operation is tedious enough on a normal construction site it is a greater problem when the job is somewhere above the Arctic Circle in Siberia.
Another specific feature of these hydraulic hammers is that their rams are not integral with the piston but are connected with the latter through a special elastic hinge. All the hydraulics of the hammer are centralized into a separate unit comprising the working cylinder, distribution valve and hydraulic accumulator. The ram can be of any size as required. The weight of the ram is selected so as to provide the impact energy at an impact velocity of no more than 6 m/sec. The weight of the ram is generally double that the the impact tool with other machines, it can be only half. This provides a high impact efficiency and increases the efficiency of the hydraulic hammer as a whole.
The power output of an impact hammer is the product of the impact energy of the hammer and the number of blows per minute. Thus, for the same power output an impact hammer can have either a high number of blows per minute and a low rated striking energy or a low number of blows per minute and a high impact energy. The advantage of the latter condition, however, is that the higher impact energy can be decisive in producing the high impact force levels necessary to demolish the work at hand. This is why these units have demonstrated outputs two or three times as high as those produce by Kone (Finland,), Krupp (Germany,) and have also outperformed those from Ingersoll-Rand.
The efficiency of these hammers is further promoted in breaking permafrost and rocks by the streamlined shape of the tool itself, which permits the operator to sink the whole hammer into the medium to a greater depth than just the length of the impact tool, i.e. a deeper layer than can be broken at one pass. Thus, there is no need to make the tool very long and the hammer can be operated as a lever, tearing large pieces away from the permafrost or rock. Other companies prohibit such handling of their demolition hammers. The strength of the tool and of the hammer body permit such operation in the case of the Russian machines.
Table 1 shows the standard sizes of the hydraulic demolition hammers based on these principles.
Table 1 Specifications for Hydraulic Demolition Hammers
Impact Energy, kJ
Blows per Minute
Hammer Weight, kg.
Ram Weight, kg.
Weight of Impact Tool, kg
Insertion Diameter for Impact Tool, mm
Hydraulic Oil Consumption, l/min
Working Pressure, MPa
Connecting Hose Size, mm
Weight of base excavator, metric tons
Maximum depth of loosening of permafrost or rock per pass, mm
The Size I has been produced in Belarus since 1982 and the Size IV in Russia since 1978. Sizes II and III have been tested as prototypes and are proving to be the most popular sizes. The design of the hammer is patented in Germany, Hungary and Finland.
Hydraulic hammers of Sizes IV and V may be used for driving small piles after some modification.
Description of Design
The hydraulic demolition hammer is mounted onto excavators as an interchangeable tool by means of an intermediate bracket which is secured both to the excavator and to the hydraulic hammer
Figure 1 shows the main parts which constitute the structure of the demolition hammer. The working cylinder (Figure 2) is essentially a body having a heat treated steel sleeve inserted therein, the latter accommodating a piston moving therein. The body of the work cylinder accommodates a check valve and a hydraulic accumulator comprising a piston with a head and rod, a bushing and a fluid spring enclosed in the cavities bored into the body and communicated with each other and with the rod end of the accumulator by means of ports.
Figure 2 Working Cylinder 1) Casing 2) Sleeve 3) Accumulator Bushing 4) Accumulator Rod 5) Piston 6) Check Valve 7) Lid 8) Check Valve 9) Piston Rod
As shown in Figure 3, a plug is provided to let air out from the cavity of the fluid spring when the latter is being filled with the working fluid.
The rod of the hydraulic accumulator is spring loaded. The head end of the accumulator is communicated with the fluid spring through a check valve intended to compensate for leaks from the cavities of the fluid spring when the hydraulic hammer is switched one and off. The work cylinder is closed from the top with a lid.
The impact portion of the hydraulic hammer is suspended from the rod of a piston by means of rubber shock absorbers. These decrease the dynamic loads acting on the rod. The impact portion moves in the guide pipe. Ports are provided in the upper and lower portions of the guide pipe and these intercommunicated by air ducts. With the impact portion moving, air flows freely from one cavity into the other one through the air ducts.
The impact portion delivers by its lower end blows upon the tool, which can move freely downwards for 60 mm along the guide of the axle box mounted on the guide pipe.
Principle of Operation
Looking at Figure 4, the ram, rod and piston are in their initial position, which is resting on the impact tool. The control valve occupies the upper position under the action of a spring mounted under its lower end position. This communicates the rod end of the work cylinder with the pressure line. It also communicates the head end with the drain line of the hydraulic system, the piston of the hydraulic accumulator occupying the upper position.
Figure 4 Operating Principle of Hydraulic Hammer — Beginning of Cycle, Ram in Bottom Position 1) Impact Tool 2) Body 3) Ram 4) Rod 5) Rod End Cavity 6) Piston 7) Check Valve 8) Drain Port 9) Head End Cavity 10) Duct 11) Control Valve 12) Accumulator Piston 13) Drain Line 14) Pump 15) Fluid Spring Cavity 17) Spring
Figure 5 Operating Principle of Hydraulic Hammer — End of Upward Acceleration 1) Impact Tool 2) Body 3) Ram 4) Rod 5) Rod End Cavity 6) Piston 7) Check Valve 8) Drain Port 9) Head End Cavity 10) Duct 11) Control Valve 12) Accumulator Piston 13) Drain Line 14) Pump 15) Fluid Spring Cavity 17) Spring
After the pump is started, the working fluid gets through the valve into the rod end of the working cylinder and the space above the piston of the hydraulic accumulator. As a result of this the impact portion starts accelerating upwards. This forces the fluid from the head end of the working cylinder through the port along the drain line into the tank, whereas the piston of the hydraulic accumulator moves downwards.
Moving on to Figure 5, at the end of the upward acceleration, the piston passes the drain port, as a result of which pressure in the head end of the working cylinder, the duct and above the upper end of the valve rises. Since the area of the upper end of the valve is greater than that of the lower one, the valve moves into the lower position, thereby communicating the head end with the pressure line and the rod end with the drain line.
This is followed by the phase of slowing the ram to a stop in the upstroke, whereby the piston forces the fluid from the head end into the hydraulic accumulator.
After the ram has stopped at the top of the stroke, it starts accelerating downward under both the force of gravity and the fluid pressure on the head end of the piston. After the impact portion has acquired a speed where it outruns the hydraulic pump, the hydraulic accumulator starts to discharge, and its piston moves upwards. At the end of the downward stroke the ram strikes the impact tool, which moves relative to the body of the hammer so the tool can penetrate the soil. Before the blow is delivered, the upper edge of the piston lowers below the check valve, whereby the head end is communicated with the drain line. As a result of this, the pressure in the head end and above the upper edge of the control valve drops down to a value at which point the spring mounted under the control valve can move the control valve upwards.
After this, the cycle can be repeated. Figure 6 shows the hydraulic schematic for the system.
The fluid spring is used in the structure of the accumulator. In this spring the pressure exceeds that in the hydraulic system by as many times as the area of the piston exceeds the area of the rod entering the cavity of the fluid spring.
Possible leaks from the cavity are compensated by the hydraulic system after the pump through the check valve, with the piston being displaced by the spring mounted thereunder.
The hydraulic hammer cannot be started unless it is applied against the work. Without the work being applied against the impact tool, the block head occupies the lowest position and the upper surface of the piston is lowered below the ports through which the fluid gets into the rod end. An attempt to start up the hammer without the hammer applied against the work results in the fluid passing freely over into the tank, and the hammer does not operate.
The hydraulic demolition hammer with fluid accumulator has proven itself both in theory and in practice. It has as rugged and simple design and is capable of performing many kinds of work. It overcomes many of the difficulties of other designs without unacceptable compromises in performance.
Intellectual-property protection, however, is deeply problematic. Previous agreements reached under US president Barack Obama’s administration could be reconstituted. But the jurisdictional enforcement of breaches is still hopeless.
One possible mechanism is to subject relevant contracts between Chinese and foreign firms to international commercial arbitration bodies in Singapore or Switzerland, designed to deal specifically with the enforcement of IP protection.
In both contracts Vulcan signed with the Chinese for the sale of the 560 hammers and boiler (1981 and 1983,) our agent Amtech wisely included the following provision:
18. SPECIAL PROVISIONS: Arbitration in Sweden or Canada
One thing that has always struck this observer as unwise is the typical American attitude that everything should be everywhere just like it is in the US. Old exporters (and Vulcan certainly had a good track record in that regard) knew better, but our voices have been ignored, especially in the years of US unilateralism following the end of the Cold War. The rise of China, whose view of life is very different from ours, should occasion the revival of a more “multilateral” approach, but such an approach will require a different style of mind than has been exhibited up until now.