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One of Vulcan's more interesting--if not necessarily most profitable--business partnerships was with the Nilens concern in Belgium. This page outlines the company and its product line.

Note: We have extensive technical information available on the Nilens product line, especially the diesel hammers. Click here if you would like to contact us about this.

The Company

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.

The early years of the relationship were exciting, with numerous trips to Europe by Vulcan executives (complete with silly questions by travel agents) and with a visit by a Belgian prince to Palm Beach.

Above: 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.

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
      • Right: basic dimensions for all three of these hammers. Shown is a very "European" configuration, strictly set up for the leaders in the back. The "Coupe B-B" is the dual-round rail configuration that Delmag made famous. The "Coupe A-A" shows a spud-type leader made up of two opposing channels. This construction was common in Russia; American contractors also employ H-Beams for this purpose. Also note the French and Flemish nomenclature. The linguistic division of Belgium is something that bedevils the country to the present.
  • "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.
The Nilens hammer in its native environment, driving sheeting using European style leaders, putting it in front of the leads. An ideal setup for sheeting, but one that didn't always catch on with American contractors.

Note the two ropes connected to the fuel pump. These rotated the needle valve on its threads and allowed it to move in and out, changing the amount of fuel sent back to the fuel tank and thus to the combustion chamber. It was also used to stop the hammer as well.

A side view of an N33 hammer in another environment, namely the pines of South Florida. Nilens' early adoption of an integrated starting device (as opposed to riding it on the back leader rails, as with the early Delmags) made it simpler to adapt the hammer to American box leaders.

The "VN-33" hammer, complete with American box leader rails, at Vulcan's Special Products Division plant in West Palm Beach. Shown at the bottom of the hammer is the adapter to enable the hammer to use Vulcan accessories. This was not a terribly successful plan; a more sensible approach was to develop a universal/filler system, which Vulcan did for its own diesel hammers in the 1980's.

Nilens "T" Series Double Acting Hammers

Nilens Pile Extractors

A "T" series hammer in the test rack at the Vilvorde plant in 1966. There were five sizes of this hammer, ranging from the T0 (400 kg-m energy, 160 kg ram) to the T4 (3300 kg-m energy, 1400 kg ram.) As with the MKT hammers, it could be used to drive sheet piles using pants, and before the diesels became predominant it did that regularly. The hammer could also be used as a concrete breaker. Vulcan had limited success with the product in the U.S., but then again it didn't fare much better with the DGH-900.

Still available (2005): a Nilens T-1 hammer, S/N N-1247, at the yard of Rush and Parker, West Collingswood Heights, NJ. The hammer is fitted for use with American "U" type leaders.

The Nilens impact extractor. The central cyliner rode up and down on the guide tube, impacting at the top of the stroke. The "monkey on a stick" concept was also used by the Menck steam hammers, albeit in a driving mode.

Excavator mounting of a diesel hammer: a Nilens diesel hammer shown mounted on a drag-line type of excavator. Excavator mounting of hammers for smaller projects has been an economical option for a long time, as this layout shows.  The configuration of excavators has changed significantly since that time, but the principle remains the same.

Cross marketing: at the left, Nilens literature for the DGH-100, which they manufactured under license. At the right, the Vulcan literature for the Nilens diesel hammers.

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.

Driven Pile Manual Volume 1a
Driven Pile Manual 1b
Driven Pile Manual 2