The hammer in question is Vulcan S/N 116, originally sold to the Florida East Coat Railroad (not far from the West Palm Beach facility) in 1897. The distinctive “open” slide bar design was changed about that time to what is on virtually every Warrington-Vulcan and Super-Vulcan hammer made since. Vulcan Foundation Equipment was able to make the spare parts Crofton required from the original detail drawings.
“Planned obsolescence” wasn’t the Vulcan way in 1897 or afterwards, which is why a 120-year old product is still driving pile and being useful to the contractor.
ZWAVE was Vulcan’s foray into the wave equation program field. It was an outgrowth of research that dated back to the late 1970’s on the magnitude of impact forces of its hammers on pile tops, so as to estimate both the loads on the equipment and the stresses on the piles. The first tangible result of this was a method and computer program based on numerical methods applied to semi-infinite pile theory; this was presented at the Offshore Technology Conference in 1987.
It became clear, however, that such a solution would not be as comprehensive as necessary, so ZWAVE was developed. Developed for MS-DOS computers, it’s “Preliminary Trial Release” (beta version) was released in 1987. The two proper releases (1.0 and 1.1) were done in 1988, after which time there was some work done the program but it had no further releases. (The user’s manual for 1.0 can be downloaded here.)
Also in 1988 was the paper describing the program, “A New Type of Wave Equation Analysis Program,” presented at the Third International Conference on the Application of Stress-Wave Theory to Piles in Ottawa, Ontario, in May 1988. This paper is available in PDF format and can be downloaded by clicking the link below.
Unfortunately ZWAVE’s copyright status makes it impossible to make the program available for download. The paper, however, shows many of the advanced features of the program which were both referenced by later authors and included in later wave equation programs.
Abstract for “A New Type of Wave Equation Analysis Program”
This paper describes a new wave equation analysis program called ZWAVE, which is a program specifically for external combustion hammers. The program is described in detail, the discussion dealing with topics concerning the program such as 1) the numerical method the program uses to integrate the wave equation, which is different from most other wave equation programs; 2) the modelling process of both cushioned and cushionless hammers; 3) the automated generation of mass and spring values for both hammer and pile; 4) the method of dealing with plastic cushions; 5) the use of a recently developed model for computing shaft resistance during driving; 6) the computation and generation of values based on basic soil properties such as shear modulus, Poisson’s Ratio and soil density; 7) the completely interactive method of feeding data to the program; 8) the method used to compute the anticipated rebound and the energy used to plastically deform the soil; and 9) the format of the interactive input of the program and the program’s output. Sample problems for the program, along with comparison of the program results with data gathered in the field, are presented.
By World War II, Vulcan’s air/steam hammer line dominated its production and revenue stream. Of all of the attempts Vulcan made to diversify is pile hammer line after that time, probably the most successful was its line of vibratory pile hammers.
Vibratory pile driving equipment represented a major departure for Vulcan, but it also represents an interesting technology in its own right. In addition to recounting Vulcan’s experience, we have a wide variety of items on vibratory technology in general:
The mid-1980’s were lean years at Vulcan. The offshore market was still down, the aftermath of the collapse of oil prices earlier in the decade. Vulcan’s own diesel program had to be stopped, plagued by design and manufacturing problems and an overvalued US Dollar. The vibratory hammer program was going reasonably well but the market was competitive. Vulcan had reached the point where it had effectively closed its own manufacturing facility and farmed out what was left.
It was in this gloomy situation that Vulcan designed and produced one of the most innovative products it had ever produced, the 400 vibratory hammer, the first of Vulcan’s high-frequency machines.
High frequency (~2400 RPM, not to be confused with the ~7200 RPM resonant machines) vibratory drivers had been produced in Europe. Depending upon the soil conditions and configuration of the pile, the vibrations used to drive or extract the pile can also be transmitted to neighbouring structures. Since European contractors drove piles more frequently in close quarters with sensitive structures than their American counterparts, European vibratory manufacturers produced high frequency machines first. Their higher frequency, combined with lower amplitude for the dynamic force, reduce the transmitted vibrations through most soils.
Vulcan’s rationale for a high frequency machine, however, was somewhat different. The first impetus for the 400 was the development of aluminium sheet piling, which made development of a driver smaller than the 1150 attractive. MKT had already developed a medium-frequency small machine (the V-2) to drive aluminium sheet piling, but the machine a) weighed over a US ton and b) had a clamp suited to steel piling, which mangled the heads of aluminium sheets.
What was needed was a lighter machine whose clamp was easier on the pile. Vulcan’s interpretation of the theoretical data led it to believe that a high frequency machine would drive the piles (which was certainly the case with the lighter sheeting sections.) The result was the first 400 vibratory hammer, designed and built in the summer of 1987.
The 400 had several innovative features:
A one piece gear-eccentric, machined out of plate with the eccentric weight burned out. The gear teeth were a much smaller pitch than their medium frequency counterparts, a feature replicated on the “A” series machines four years later. The small pitch ran more quietly an dispensed with the need for surface hardening.
A clamp that was burned out of plate. The cylinder bolted to it used the flat end of the rod as the movable jaw. This only left a shallow round dent in the sheeting when clamped.
The “U” configuration which wrapped around the exciter case and transmitted the force from the crane to the pile during extraction. This and other features were subject to U.S. Patent 4,819,740. (This patent has been a nuisance to Vulcan’s competitors for long time, cited in several patents from inventors at HPSI, APE, J&M, ICE and MGF.)
It was the first Vulcan pile driving machine to completely dispense with castings.
The result was a machine that weighed only 1100 lbs.–half of the MKT V-2–and still drove the piles successfully.
The 400’s first job, driving aluminium sheet piling for a marine in Ft. Pierce, FL, 15 September 1987. (Note: the designation “400” was an attempt at an equivalent rating with medium-frequency machines. The hammer actually turned 200 in-lbs of eccentric moment 2400 RPM, for a dynamic force of 17 U.S. tons.)
Another view of the 400. The cruciform suspension added bias weight to the machine. Note that the clamp is rotated differently than the first unit; this is due to the fabricated design, which allowed easy orientation of the clamp body for various sheeting sections.
The entire 400 package. The power pack, Vulcan’s first open unit, was an HPSI unit.
The 400A. The 400 was a successful hammer, but suffered from two drawbacks: the curved lower surface made attaching accessories such as caisson beams difficult, and the suspension was not configured for down crowding, which limited excavator operation. The 400A was designed to overcome both of these problems, although Vulcan’s woes a the turn of the millennium limited the company’s ability to take advantage of them.
The 1400, driving sheeting for a creosote plant environmental remediation in Chattanoga. The 1400 incorporated many of the features of the 400, including the curved eccentric case (which was mated to the 7″ clamp.) The original suspension was an H-beam, but this proved too light for bias weight, and was replaced by the cast unit shown.
The Vulcan 2800, the largest of its high-frequency machines, driving H-beams in Cairo, Egypt. It was an innovative design, and the first to actually wrap the hoses through the suspension. Unfortunately its introduction was plagued with component problems. The most serious of these was the Morse shear fenders used for the suspension springs. Having been used successfully by ICE and other manufacturers, the Morse factory began to experience quality problems of its own around the time the 2800 was introduced. Note the use of aluminium bearing covers. These were used to afford better heat dissipation to the bearings. The high frequency machines were especially prone to overheating because of their higher rotational speed, although Vulcan also used them on their other machines, if for no other reason than they looked good.
Vulcan 2800 hammer, driving sheet piles for a cofferdam used in the construction of a new bridge for U.S. 41 over the Sequatchie River in Tennessee.
In 1984 Vulcan re-entered the vibratory hammer market with the introduction of the 1150 vibratory hammer. This hammer made its debut on a project in Bangor, Maine for Cianbro Construction. More suited for the American market and adequately powered, these machines were far more successful than the Vulcor hammers had been.
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 accommodate 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.
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.
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.
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.
Vulcan 2300 driving large pipe at Dixie Sand and Gravel, Chattanooga, TN, late 1980’s.
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.)
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.”
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.
Below: a 2300 on the job driving h-beams in Portsmouth, Virginia, in 1990. The contractor was Tidewater Construction. A diesel hammer can be heard driving piles in the background for part of the video.
Below: the 2300L extracting soldier beams in Atlanta, Georgia, in December 1990. The fact that these machines can both drive and extract piling without modification is part of their appeal.
Below: a video of the installation of bearings in the 2300L, and a little “tour” of PACO’s yard.
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.
The basic components of a vibratory hammer system, featuring the Vulcan 2300A with the 7″ clamp.
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.
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.
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.
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 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 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. Current service and support for these units is furnished by Pile Hammer Equipment.
Vulcan’s first venture into the vibratory market took place in the 1960’s with the introduction of the Uraga electric vibratory hammer from Japan, which Vulcan marketed as the Vulcor Vibratory Hammer.
Vibratory pile driving technology had been developed in the Soviet Union. One of the first countries to pick up the technology was Japan. With its volcanic soils, it is an ideal place for a vibratory hammer to be used.
The Uraga/Vulcor machine was a departure in that Uraga reversed the rotor and stator on the electric motors and positioned one motor inside of each eccentric. This resulted in a vibrator with a more direct drive than has been seen before or since, making for an efficient construction and operation.
Unfortunately the width of the machine clashed with the normal American practice of setting the sheets before driving, which requires either that the vibratory hammer be narrow enough (less than 355 mm) at the throat or use an extension (which adds to both the vibrating mass and hanging weight of the hammer.) Some Uraga machines also suffered from misalignment of the eccentric bearings, a function in part of the “modular” construction of the machines (to increase the number of eccentrics, it was simply necessary to add another “stack” to the unit.
All of these difficuties, combined with American contractors’ aversion to electrics on the job, put the Vulcor at a disdavantage to other vibratories coming into the U.S. By the time Vulcan moved to West Palm Beach, the Vulcor programme was pretty much over and it would be another twenty years before Vulcan would attempt a vibratory hammer again.
At one point or another in its history, Vulcan attempted to produce or market every type of pile driver made. Probably the persistently least successful type were the diesel hammers. Vulcan’s failure to manufacture and/or market a widely accepted diesel hammer was a significant long-term problem for the company.
Nevertheless diesel hammers are an important and interesting type of impact pile driver. This section of vulcanhammer.info discusses diesel hammers in general and Vulcan’s several attempts to enter the market.
Competitors: just about everyone has them. Here are the field service manuals for two which Vulcan encountered for its diesel hammer:
Kobe Diesel Hammer Field Service Manual: for their K13, K22, K32 and K42 hammers. The Kobe hammers were the first diesel hammers marketed in the U.S. on a “sell them cheap and sell a lot” philosophy, and this was especially true in the South, where they were very prominent for many years. This idea has been repeated with the “Chimag” hammers which are virtually ubiquitous in the U.S. today.
IHI IDH-J22 Field Service Manual. IHI was Menck’s representative in the Far East, and in China Vulcan met and bested them. IHI also developed an interesting diesel hammer where the fuel pump actuator was powered by the compressed gases in the combustion chamber. Unfortunately the mechanism tended to jam when dirty, which was about all the time with a diesel hammer.
Vulcan’s last foray into diesel hammers was, in many ways, one of the most interesting ventures in the company’s history. It was certainly one of the most involved.
In 1987 Vulcan first met with Russian (then Soviet) trade representatives in Washington concerning marketing Vulcan’s offshore hammer line in the Soviet Union. It’s interesting to note that the Soviet trade office was just around the corner from the hotel where Ronald Reagan was shot in 1981. The Soviet Union had enormous oil and gas reserves and, not to be outdone by the Chinese, were beginning to solicit foreign assistance in exploiting these resources. (Even having lost the other republics in the break-up of the Soviet Union, Russia remains rich in hydrocarbon reserves and a major producer.)
The Soviets had other ideas. Never much on spending their hard currency on lining American corporations’ pockets (they weren’t well endowed with hard currency to start with,) they invited Vulcan’s people to Moscow with another objective: to convince Vulcan to market Soviet pile driving products.
Vulcan’s personnel made the trip in April 1988, and were regaled with several interesting types of equipment, including the vibratory hammers (native to the country) and the concrete pile cutter. But the most significant products were the Russian diesel hammers, which they demonstrated to Vulcan’s personnel at the Central Testing Facility (TsNIIP) in Ivanteevka, northeast of Moscow. (In addition to scientific testing, this facility also supplemented this activity by raising pigs.) These were the water cooled variety, produced at their plant in Sterlitamak, near the Urals. (More information about these can be found here. Vulcan personnel also went beyond Ivanteevka to Zagorsk to visit Russian Orthodox Church personnel.)
Although the hammer was simple and ruggedly built (something Vulcan liked to see in a product) the water cooling was a problem. American contractors never took to water cooling diesel hammers, even though it was certainly, in theory at least, the best way to do so. It was an obstacle the Japanese such as Kobe and Mitsubishi had to overcome when they marketed their hammers in the US in the 1970’s, and they largely did so with very competitive pricing. Neither Vulcan nor the Soviets, the latter working through their trade organisation, were prepared to really get the details of such an arrangement, and so Vulcan returned to the US empty handed. (Vulcan did get a chance to propose their offshore hammers, but this too came to nothing.)
At this point all seemed at a dead end, but by 1991 the Soviet Union was unraveling and Vulcan had established meaningful contact with some of the people it has met three years earlier. Given the economic conditions in Russia and Vulcan’s own priorities, the emphasis had shifted to Vulcan acquiring Russian equipment and technology, and the diesel hammers were high on the list.
The following year Vulcan personnel visited Russia again with the idea of acquiring the Sterlitamak hammer. Sterlitamak was the only Russian organisation which actively exported diesel hammers, and the pricing they had proposed (facilitated by the slide of the ruble) would give Vulcan what it was looking for: a proven diesel hammer, economically priced, which would allow it to repeat L.B. Foster’s blitz with the Kobe hammers twenty years earlier. (This kind of blitz was actually carried out by some of Vulcan’s competitors with the Chinese made hammers later in the decade and into the new millennium.)
Sterlitamak, however, got cold feet at the idea of selling their product at the price they originally proposed, so Vulcan was forced to look elsewhere for equipment. In doing so they discovered that not only did other manufacturers exist, but that they produced air cooled hammers, which is what Vulcan was looking for to start with. The first plant Vulcan visited was in Lyubertsy, south-east of Moscow, shown in the video below.
Vulcan purchased a few of their 2500 kg ram hammers. Below: the “before” (left, September 1993) and “after” (right) of the Lyubertsy manufactured diesel hammers. The biggest challenge (as with Nilens) was to move the fuel tanks (one on each side of the hammer, like the old XJ6 Jaguars) up and flatten them to get the hammer into 26″ leaders. Vulcan rechristened it the V25 Series 1 hammer.
Vulcan also acquired 1800 kg ram hammers from a plant in Podolsk, south-west of Moscow.
Almost two years later Vulcan visited a military plant in Bryansk, which produced equipment for its railroad troops, as shown below.
From this plant Vulcan purchased some 1250 kg ram hammers.
What Vulcan ended up with were hammers which were economical enough, but weren’t intended for export. (They suffered from a common Soviet problem: well executed design, but not so good execution in manufacturing. The Bryansk hammers, being from a military plant, were the best.) Vulcan was required to make modifications to the Podolsk and Bryansk hammers as they did with the Lyubertsy ones.
At this point things went awry on Vulcan’s end. Vulcan certainly did manage to deal with the technical and quality issues in front of it. But it could not come to an internal consensus on how to market them; the Kobe model wasn’t universally accepted. In the midst of this Vulcan’s other problems took precedence and the Series I program fell by the wayside.
Vulcan never intended the Series I hammers to be the last word on this. It commissioned the design of an air cooled “Series II” of hammers which ranged in size from 1250 kg ram to 7500 kg ram. Vulcan’s idea was that they would have a hammer which could be built in Russia, the US or wherever manufacturing was the best. The series design was completed but none were ever built, and so Vulcan never got the chance to overcome its past history and bring a viable and economical diesel hammer to market.
With Nilens gone and the LPG hammer unsuccessful, in 1978 Vulcan found itself without any kind of internal combustion hammer. It passed up the opportunity to purchase the Link-Belt diesel hammer line and attempted to develop its own. The effort that resulted was the IC-30/30D/33D hammer line.
The IC-30/30D driving H-piles for the Veterans Bridge in Chattanooga, TN, in 1983. The sticker on the upper cylinder is for Mississippi Valley Equipment, Vulcan’s largest onshore dealer at the time. This was one of the hammer’s success stories.
The first IC-30 in the assembly area at Vulcan’s Chattanooga facility.
The one successful “spin-off” from the diesel program: the universal adapter base (above) and filler system developed for the diesel hammers. They also proved to fit other diesel hammers and were in the company’s product line until it was merged in 1996.
The one successful “spin-off” from the diesel program: the universal adapter base and filler (above, in this case a pipe cap) developed for the diesel hammers. They also proved to fit other diesel hammers and were in the company’s product line until it was merged in 1996.
Vulcan’s starting point was the Nilens N-33 hammer, which was equivalent to a Delmag D-12. In the course of development, however, Vulcan attempted to make “improvements” on the Nilens designs. Most of these, unfortunately–the use of a single-piece casting for both cylinders, ram and anvil and others–represented an attempt to adapt the diesel hammer to Vulcan’s customary manufacturing methods. It was mostly these which proved the downfall of the line.
The first hammer, the IC-30, was completed in 1980. After some testing the hammer was released for the market, and the name was soon changed to the 30D or 33D to get away from the “IC” (too much like “ICE” or International Construction Equipment for Vulcan dealers’ tastes.) It achieved some successes, but its weaknesses made it expensive for Vulcan to keep it in the field. Compounding the technical problems was the strong U.S. dollar at the time, which made the German made Delmag relatively cheap.
All of these contributed to the eventual decision to recall the hammer. By the mid-1980’s Vulcan was once again out of the diesel market. By that time the vibratory hammers were achieving success and Vulcan’s product line was broadened in another way.
When Vulcan began to deal with Charles Nilens S.P.R.L., they were located in Vilvorde (Vilvoorde) at 52, Avenue de la Station. Vilvorde is north of Bruxelles (Brussels); it is the same city where William Tyndale, the first person to translate the Bible directly from the Greek and Hebrew into English, was executed for his activities in 1536. In the late 1960’s Nilens secured new offices at 7-14 Houtemstraat in Peuthy (Peutie), also in Vilvorde, and were then known as Materiel Nilens (MANIL) S.A.
Vulcan’s first agreement with Nilens came in June 1963, where Nilens agreed to be Vulcan’s distributor in the then European Common Market’s six countries: the Netherlands, Belgium, Luxembourg, France, and West Germany. In September of the same year the two companies signed an arrangement whereby Nilens would manufacture under license the Vulcan product line. At the time Nilens’ managing director was Jean Willy Nilens. Vulcan also distributed portions of Nilens’ product line in the U.S., as will be described below.
A view of Nilens’ shop in Vilvorde. Vulcan personnel, be they field service people or corporate executives, and no matter how “exotic” the destination, spent a lot of time in machine shops and foundries. In the front is a cylinder in process for an N46 hammer; in this case, the cylinder is one piece. (Most Nilens hammers used a two piece cylinder.) The integration of fabricated and cast pieces (detailed below) had no parallel with Vulcan equipment. In the back is the boring and planing equipment that is essential to the manufacture of pile driving equipment.
European travel wasn’t all machine shops, though: my mother (in the centre) and my father (to her left, your right) at Maxim’s in Paris, probably 1966. Photo by Jaques Sabrou, Paris.
Nilens for its part made a few Vulcan hammers under license, but the predominance of diesel hammers in Europe made the appeal of air/steam hammers limited.
The Product Line
Nilens’ product line broke down into four parts:
Single-acting diesel hammers, from Vulcan’s standpoint, the most important part of Nilens’ product line. Nilens produced three single acting diesel hammers:
N33, with a ram mass of 1250 kg and a rated energy of 3125 kg-m
N46, with a ram mass of 1800 kg and a rated energy of 4500 kg-m
N60, with a ram mass of 2400 kg and a rated energy of 6000 kg-m
“T” series double-acting air/steam hammers (left), similar to the MKT “B” series machines (9B3, 10B3, 11B3). These were primarily intended for installing sheet piling.
Impact pile extractors, held together using a cable wrap system (right). They were a superior extraction machine to Vulcan’s extractors, albeit more complex and expensive.
Pile driving rigs, with leader mast and carriage. This is more typical of European manufacturers (Junttan is a good modern example of this.)
Three of these are described below.
Nilens Diesel Hammers
Operation of Nilens Single-Acting Diesel Hammers
The piston, which in fact is the ram, is raised by the trip mechanism, which is attached to the hoist line. Air enters the cylinder as the piston uncovers the exhaust ports. When the trip mechanism makes contact with the cam, the piston is released automatically. The trip mechanism continues up until it is arrested and held by a spring loaded dog.
Diesel hammers are generally either of a cast construction (like the current Delmag hammers and their progeny) or fabricated (as with the Russian diesels or MKT.) Nilens (along with the older Delmags) was something of a hybrid; an iron ram rode in tubular steel cylinders, with a cast “sleeve” complete with cooling fins fabricated into the hammer around the combustion chamber. When Vulcan designed its own diesel hammers, it went to a cast lower cylinder, with uninspiring results.
The piston falls due to gravity and depresses the cam, which actuates the fuel pump. The fuel pump injects a measured amount of fuel oil into the concave top of the anvil.
The Nilens’ fuel pump was unique in that it used an internal cam/plunger instead of the external type common on Delmag and other fuel splash delivery systems. It was not a positive displacement pump either; it was a pressure compensated one, with fuel entering (and excess fuel returning) through a needle valve in the top of the pump. When manufactured properly, the pump worked well, but manufacturing and design variations were the chief weaknesses of an otherwise good diesel hammer.
The piston blocks the exhaust ports as it continues to fall. The cylinder is now a closed chamber, between the piston and anvil, and compression builds up. The convex end of the piston strikes the fuel oil in the top of the anvil and sprays it up into the hot compressed air in the compression chamber, which causes it to ignite. The resulting explosion drives the piston up and adds to the energy already delivered to the anvil by the impact of the piston. The piston uncovers the exhaust ports on the upstroke, permitting the exhaust gases to escape and fresh air to enter the cylinder for the next cycle. To lubricate the piston and cylinder wall, oil is automatically ejected from the reservoir in the top of the piston. The anvil is lubricated by four grease fittings.
European horizons for the DGH-100: an advertisement by Vulcan’s Belgian partner Nilens, who was licensed to manufacture and sell the hammer.
The Vulcan literature for the Nilens diesel hammers.
Another shot of the Nilens extractor, in this case pulling H-beams, 1964.
Another view of the Nilens hammer taken in front of the pines of South Florida.
Vulcan was able to sell and rent a number of Nilens diesel hammers in the U.S.; some of them were operational for many years. They ended up outlasting the company itself. In 1976 Willy Nilens fled to Spain; the company went into receivership, the product line was acquired by Intermat, and the Nilens concern passed into history.