Direction for Setting Column Keys

For those of you who still have column keys on your Vulcan hammer, these are diagrams for setting them, from 1963.  The cylinder keys are shown above and the base keys are shown below.

More on base column keys is here.



An Overview of Tapered Pipe Threads, and Their Application at Vulcan

It’s hard to imagine that much of our technology is underpinned by very old, basic standards that year after year simply “do their job” without much regard.  One of those is tapered pipe threads.  This is a brief overview of same, and specifically the “National Pipe Taper” or NPT threads.  Much of this material comes from the American Machinists’ Handbook by Fred Colvin and Frank Stanley, Second Edition (1914).

Most screw threads are “straight threads,” i.e., the diameters of the threads (outside, pitch, inside) are constant along the length of the threads.  Tapered threads by definition can only work for a limited length, but when pipes are connected, that’s fine.  Like any other taper lock, tapered threads have an additional wedge effect, which means that they can seal fluids in the pipe (or outside of it.)

Originally these pipe threads were referred to as “Briggs standard threads” after Robert Briggs who came up with them.  In 1886 these were adopted as a standard by the American Society of Mechanical Engineers and various manufacturers.  They have varied little since that time.  They have been a durable standard for leak-resistant, permanent (and semi-permanent) connections ever since.

An overview of the “Briggs standard thread” is below.


As noted above, only the “perfect” threads (in one way or another) contribute to the sealing/joining of the pipe thread.

The overall dimensions of the various sizes of tapered pipe threads are shown below, with a diagram showing the types of gauges used to check the threads.


The tapered reamer was one item Vulcan seldom used; the usual procedure was to tap drill the hole and then use a tap for the threads in question to put the threads in the hole.  Below are some tap sizes for NPT (National Pipe Taper, or Briggs) threads.

Tap drills for National Pipe Taper threads.  The “Briggs” values are for the NPT threads; the Whitworth are for their UK counterpart, which were never as popular as the NPT/Briggs threads.  The drill size for the 2″ pipe tap should read 2 3/16″.  In reality there is a little “wiggle room” for the tap drill size, as is the case with straight threads.
When threading a pipe, a die is generally used. The “actual inside diameter” can vary; the table here is closely related to Schedule 40 pipe. It can obviously be smaller for higher pressure applications and those where the mechanical strength of the connection needs to be larger (as with pressure gauges.)

A more detailed treatment of the threads as the pipe and hole threads interface is shown below.

Theoretical standards for the NPT/Briggs standard pipe threads, with a more complete treatment of the perfect and imperfect threads, which is important in the design of pipe threaded holes, specifically how deep they need to be.  This comes from “The Crane World” magazine, January 1919, from the Crane Company, a leading manufacturer of valves.  When the Crane Company was established in 1855, it was near Vulcan’s facility and in fact Vulcan’s founder, Henry Warrington, was Crane’s first customer, placing an order for box castings (a notoriously difficult shape to cast) and other parts for locomotives, which Warrington was making at the Vulcan Foundry.  In his later years, after his sons were active at Vulcan and their other activities, Warrington worked at the Crane Company.

The pipe taper standard was wildly successful, and is used in everything from home plumbing to high-pressure hydraulics.  In the oilfield the standard was so successful that it’s widely used even in places where metric standards are the norm

As far as Vulcan is concerned, Vulcan used the standard in many of its products, both the air/steam hammers and later the hydraulic vibratory hammers, where they were used for pressures up to 5000 psi.  This was due to their durability, ability to resist vibration (a must with any Vulcan product) and their flexibility in radial orientation.  With a pipe thread there is a point where it’s “tight” but it can generally be tightened a little further, thus allowing some flexibility in the orientation of parts.  One thing Vulcan learned with pipe threads was, although they are designed to seal with their taper, the use of some kind of “pipe dope” or sealant is very important.

Below are some applications of pipe threads in Vulcan hammers.

A Vulcan drawing “callout” for pipe threads, in this case small ones for the grease fittings on the Hydra-Nut.
The “outside” of the Hydra-Nut (U.S. Patent 3,938,427.) Introduced in the 1970’s to directly replace the cable nuts (as shown above,) the Hydra-Nut simplified the process of tensioning the cables. The Hydra-Nut was screwed on without the cast thread protector cap on the top, the cable was lightly tensioned with a “manual jack,” the threaded sleeve was screwed down on the cable fitting and tightened against the jack body, the manual jack removed and thread protector cap replaced (aligning the flats on the cable fitting with those on the cap,) then the chamber was pressurised through the grease fittings to the pressure where the cables would have their proper, full tension. The weakness of the Hydra-Nut was in the grease fittings; should dirt or paint get in them, the chamber would depressurise and the cables would be loose. This was more probable when Zerck fittings were used than with the button head fittings as shown. Vulcan addressed this issue in the 1980’s with the Auto-Jack, which altered the Hydra-Nut by adding an internal cable nut with the integral jacking cylinder, which was then depressurised when the cable achieved proper tension.
A call out for a pipe flange on a Vulcan offshore hammer. Note that now, instead of tap “drilling,” we’re forced to bore the hole before putting the pipe tap in.
A close-up of the 040 cylinder during exhaust. The large hose is the steam hose that powers the hammer, the small hoses are the Vari-Cycle hoses that shift the trip shifter one way or the other to vary the stroke. The hose is connected to the hammer through a connector which is screwed in the large pipe caps on the double pipe flange in the front of the hammer.
Vulcan 85C Hammer.  Note that, towards the top of the cylinder are two pipe plugs.  These are installed into tapped tapered pipe fitting holes.  (There are actually four of these, two are covered by the plate referred to as a “belly band.”)  Behind them is a cored passageway between the valve and the top of the cylinder.  These holes helped to support this core during casting but had to be plugged for use, and the pipe plugs were the ideal way of doing this.

Pile Buck Ads 5: Vulcan 530 in Offshore Leaders —

For the last of the “Pile Buck Ads,” a photo of the Vulcan 530 hammer is featured in offshore stub-type leaders. The 530, introduced in 1978 for driving pipe piles offshore in the Gulf of Mexico, was and is used in a wide variety of pile driving projects. In this case it’s shown to be […]

via Pile Buck Ads 5: Vulcan 530 in Offshore Leaders —

Hong Kong and the Straits of Hormuz: It’s Amazing It Took This Long

Although Vulcan exported its pile driving equipment from the start, it was it’s foray into the offshore oil business that gave Vulcan a truly international perspective.  That perspective put some of the world’s “hot spots” into its field of interest, and two of them are very active these days: Hong Kong and the Straits of Hormuz.

Most of Vulcan’s activity in East Asia was in South East Asia; thus, its main “centre of focus” for its equipment and travelling personnel was Singapore.  With Vulcan’s sale of its first pile hammer package to the Petroleum Corporation of the People’s Republic of China in 1981, Hong Kong became of interest.  At the time China was a very closed country; Hong Kong acted as a window to the world, although from a commercial standpoint Vulcan didn’t use it that way.

The UK’s decision to return the entire colony to the People’s Republic when the lease on the “New Territories” (the area of Hong Kong north of Kowloon and excluding that and Hong Kong Island) expired in 1997 was formalised in 1984; however, rumours swirled about a handover years before.  The attitude of Vulcan’s business associates towards such a reintegration was bluntly summarised by one of them: “They’ll screw it up.”  The contrast between the state socialism of the People’s Republic and the free-wheeling capitalism of Hong Kong was pretty stark, and it was hard to imagine that the former would allow the latter to go on in the same way for any length of time.

Up to now the PRC has surprised many people with the relatively light hand they’ve actually had on Hong Kong.  Some of that was the desire of the PRC to have Hong Kong be a “model province” for the “capitalist roaders” in the rest of the country, an incentive for economic development.  Another factor was to make the reintegration of the greatest “wayward” region–Taiwan–more attractive to those on the island.  Still another was the PRC’s desire to maintain Hong Kong as an economic powerhouse and thus contribute to the country’s overall prosperity.

Such desires have butted up against two things: the linking of Hong Kong’s people of free expression to economic freedom, something the mainland has avoided, and recent changes in the Chinese leadership.  Now the latent conflict of the two is out in the open.  The Chinese leadership will have to tread carefully; if they don’t, they could fulfil my business associate’s prophecy and China will be the worse for it.

The Straits of Hormuz has been the central “choke point” of world oil shipments for many years.  The Persian Gulf is ringed by oil-rich nations and 20% of the world’s oil supply passes through it.  That vulnerability really came into public consciousness with the Yom Kippur War and the first “oil crisis” of 1973.  It wouldn’t take much to mine or otherwise sabotage the Straits of Hormuz, which increased the Western military interest in the place.

The countries that ring the Gulf have been aware of this vulnerability for a long time.  Saudi Arabia built its Yanbu oil terminal on the Red Sea in an attempt to provide an alternative to the Straits.  Vulcan’s first contact with and sale to the Korean contractor Hyundai was due to the fact that they were contracted to build this terminal and need pile driving equipment to accomplish it.  On the other side Iran was looking to build a major port at Chabahar on the Indian Ocean using Vulcan’s long-time customer Brown and Root, but the 1979 Revolution stopped that effort.  (The Islamic Republic built a port there, currently operated by India.)

With the Sunni-Shia divide and the ill-conceived war in Iraq (which deprived the two sides of a buffer) the Straits had opponents on both sides, and it was only a matter of time before it would become a hot spot once again.

The amazing thing in both these situations is not that they’re points of conflict, the amazing thing is that it has taken as long as it has to reach the current situation.

Pile Buck Ads 4: Link Belt Diesel with a Mandrel —

The fourth in our series on the ads which Pile Buck allowed to run was this shot of a Link Belt 520 driving shell piles using the Vulcan Expanding Mandrel. The mandrel’s history and shell piles in general are discussed here. The Link Belt 520 is an interesting story in itself. The diesel […]

via Pile Buck Ads 4: Link Belt Diesel with a Mandrel —

Port of Singapore — Construction and architecture

The Port of Singapore refers to the collective facilities and terminals that conduct maritime trade, and which handle Singapore‘s harbours and shipping. It is ranked as the top maritime capital of the world, since 2015. Currently the world’s second-busiest port in terms of total shipping tonnage, it also trans-ships a fifth of the world’s shipping containers, half of the world’s annual supply of crude oil, and […]

Vulcan hammers gained their reputation in part because they were simple, thus free from breakdown and repairable to a great extent on a derrick barge with crews that were not full time mechanics. However, there eventually came a time when a hammer needed an overhaul. Vulcan field service personnel spent a great deal of time on these kind of extended repairs, where it was necessary to put the hammer into a machine shop, disassemble the hammer, clean and recondition the workings, and reassemble the hammer. A hammer with extended exposure to salt water could prove difficult to disassemble; shown here is a Vulcan 200C getting that kind of treatment in a machine shop in East Asia. Note the use of a jack–common with this kind of equipment–to force the components of the machine apart.

Singapore and its environs was an important place for Vulcan, because it was the gateway–and frequently the repair place, as you can see on the right–for many of the Vulcan hammers that operated in Southeast Asia.  Southeast Asia, with its large regions of relatively shallow water, was fertile ground for Vulcan hammers.  Many of Vulcan’s customers–including McDermott, Jardine and Brunei Shell–used its equipment extensively in this region.

via Port of Signapore — Construction and architecture

STADYN Wave Equation Program 11: Application of the STADYN Program to Analyze Piles Driven Into Sand —

The newest update for the STADYN research project is available: Download Application of the STADYN Program to Analyze Piles Driven Into Sand The abstract is as follows: Abstract: The STADYN program was developed for the analysis of driven piles both during installation and in axial loading. Up until now the test cases used were in […]

via STADYN Wave Equation Program 11: Application of the STADYN Program to Analyze Piles Driven Into Sand —

Pile Buck Ads 3: Nilens Diesel Hammer Driving Sheet Piles —

The third in our series of ads for Pile Buck include this one, showing a Nilens diesel hammer driving sheet piling using a “spud” or “rail” type leader in the back. Nilens was one of Vulcan’s more interesting adventures in pile driving equipment. The method used is a typically European practice that has found […]

via Pile Buck Ads 3: Nilens Diesel Hammer Driving Sheet Piles —

Hand drafting – TECHNICAL INK PENS — Construction and architecture

From the first time it produced drawings (the oldest on this site goes back to the 1870’s) until the late 1950’s, Vulcan produced all of its drawings using pen and ink, as described below (although I’ll bet that many weren’t drawn using the Rapidograph type pen shown below!)  Many of these were drawn on linen.  Above is an example of one, the general arrangement for the Vulcan 18C, from 1939.  There are many more examples of these on the site.

More about Vulcan engineering is here.

via Hand drafting – TECHNICAL INK PENS — Construction and architecture

The Art of William H. Warrington

William-H-WarringtonThis post is something of a departure, in that it features the pencil sketch art of my great uncle, William H. Warrington (right, from his carte de visite.) But first some background is in order.

William H. Warrington was born 17 September 1846, grew up in Chicago, Illinois. He became the manager of the Vulcan Iron Works, the family business. Although he was very prosperous in business, he had an artistic side to him, and here we’ll present some of his pencil sketches. As is frequently the case in my family, I don’t have much “backstory” narrative for these, but what I do know I will share.

As best I can tell, most of these date from the 1860’s, when he was in his late teens. Some have an English or Scottish settings, and this may be from travels in the British Isles. His father Henry was an immigrant from Manchester, England, and his mother Isabella McArthur Warrington came from Scotland. Both made return trips to their native land; Henry in fact did not become a U.S. citizen until 1870, almost thirty years after he first came to the U.S.

Signature card for the seniors of the Chicago High School, 1864. William H.’s is at the lower right.

Above: Two studies of young women.

Below: large house plans, 1860’s style. The various rooms of the house are as follows:
1. Kitchen
2. Scullery
3. Store Room
4. Breakfast Room
5. Stairs
6. Lobby
7. Hall
8.Dining Room
9. Library
10. Drawing Room
Alloway Kirk, Scotland.
Winter Quarters. A reminder of the great Civil War that was going on to the south. William H.’s father was busy producing cannons and cannon balls for the Union, while his uncle, Union general John McArthur, was leading the “boys in blue” at places like Shiloh and Vicksburg. His nephew Chet married the daughter and granddaughter of Confederate veterans, who had an entirely different view of Mr. Warrington’s products and relatives!
Sketch from Nature? An odd title, but it’s a nice view of the plank sidewalks that were current in his day.
Rowing has come a long way from this bucolic view.
Although it’s tempting at first to place this in Europe, the American flag gives away which side of the Atlantic it’s on.
Looks to me like something out of Lord of the Rings, but being nostalgic about English country life (and, indirectly, that over here) was one of the reasons J.R.R. Tolkien wrote his masterpiece.
Another rural house scene.
The house where William H. actually grew up, in Chicago. Note in the lower right hand corner the unusual way the artist “signs” his work.

William H. Warrington died 11 August 1921.