Mating Pipe Piles to Pipe Pile Caps

Pipe pile caps have been around as long as pipe piles, but mating them to a pile hammer via a pipe cap may be new to some users.  The diagram above (which, as you can see, dates from 1931) shows how this is done.

The cross-section shows three diameters of pipe piles mating with a pipe cap.  Pipe caps typically have steps to mate with more than one size of pipe pile.  It’s also possible to drive pipe caps “flat face” (with no steps) but you lose the alignment assistance of the cap when you do.

The outer two pipes mate with “male steps,” those which face the inside diameter of the pipe.  It’s necessary thus to know the ID of the pile, which usually means the OD and the wall thickness.  A little clearance is allowed to make mating simpler and to take into account the fact that pipe pile isn’t always perfectly round (especially at the ends, where it gets bent.)

On the small onshore caps, the steps are typically straight.  On the offshore caps, Vulcan typically put in a draft angle to make stabbing the pile easier.

With caps with multiple steps, it’s possible for the steps to interfere with each other because the diameter of one step is too small to accommodate the OD of the pile below it.  To avoid this problem requires some layout before the cap is machined.

Male pipe caps can be used with wall thicknesses thinner than originally intended with the use of welded shims.

The inner pile mates with the “female” portion of the cap, i.e., the OD of the pile.  This eliminates the ID mating problem but requires a completely different cap design.

Some other information is shown below.

Vulcan’s choice of pipe cap design deserves some explanation. Below is a diagram of the three basic types of pipe caps in use, both during the heyday of Vulcan offshore hammers and now. Male Caps (left) were the standard Vulcan configuration. The cap is stepped for different pipe sizes and is fitted to the I.D. of the pipe. To align the leads and the pile (especially important with the batter piles common offshore) the pipes were passed through a stabbing bell (at the bottom) which itself was stepped to the O.D. of the piles. The arrangement was preferred with Vulcan’s customers (especially those in the Gulf of Mexico) because the cap is easy to modify and shim for different size piles and the stabbing bell is easy for the crane operator to thread the hammer assembly over the pile for driving. Female Caps (centre) was most common with the Menck hammers. All of the steps were mated to the O.D. of the cap. Although mating it to piles was more straightforward, since the maximum plate moment of the cap was in the centre, the thicker centreline of the male cap was an advantage. Flat Face Caps (right) were preferred by the diesel manufacturers such as Delmag (and later IHC and Pileco.) Since there are no alignment steps on the cap, all of the alignment takes place with the adjustable keys under the cap facing the O.D. of the pile. (It’s better to have two sets of keys than the one shown.) Although the cap is much simpler, the carrier required for the cap and keys can be complicated to produce.

Vulcan Onshore Tips: Introduction and Index

Not widely appreciated when they were first issued in 1973, the Vulcan Tips are in a sense “made for the internet” in their format.  They were issued in print until the late 1990’s.  They went beyond the Vulcan Data Manual–and at the time the Field Service Manual–in providing practical suggestions for proper operation of Vulcan hammers.

There were two sets of Tips, onshore and offshore, corresponding with the two markets Vulcan sold and serviced its products into. The Vulcan Offshore Tips have been on this site and its predecessors since 1998. In the case where the specific onshore tip has an offshore counterpart, we’ve linked to the offshore tip. In cases where we’ve covered the same information in other ways, we’ve linked to that too.

Many tips refer to factory parts and service. Obviously these are no longer available, but there are sources for most of what is contained in these tips.

As is the case with the offshore tips, we’ve added commentary where appropriate. We also strongly recommend that you acquire the Guide to Pile Driving Equipment for more information and several field service manuals for Vulcan hammers. Some of the tips are covered in that volume and are linked appropriately.

Vulcan Onshore Tip Number Subject Corresponding Offshore Tip, Comments or Other References
001 Head Gasket/Single Acting Hammer 001
002 Checking Slide Bar
003 Valve Flutter See also Tip 63.
004 Reduced Hammer Energy Guide to Pile Driving Equipment
005 Lubrication 023
006 Keeping Ram Keys Tight
007 11 Rules for Pile Driving
008 Ram Keys Too Tight 002
009 Blow Count/Energy
010 Tightening the Packing Gland 003
011 Storage
012 Trouble Shooting 013
013 Adaptation of McDermid Base
014 Vulcan Extractors
015 Base Column Keys
016 Piping Do’s and Don’ts See also Tip 64.
017 Exhaust Mufflers Decelflo Pile Hammer Muffler, and the Thruflo Geothermal Muffler
018 Ram Key Adjustment For Vulcan Hammer Series #2, #1 and #0 only.
019 Valve Liner
020 Extractor Bumper Conversion
021 Slide Bar Shim
022 Replacing Slide Bar Babbitt
023 Inserting New Ram Point in Ram Guide to Pile Driving Equipment
024 Removing Broken Ram Point 004
025 Side Channel Modification
026 Column Removal
027 Bushing Replacement 014
028 Installation of Blind Piston Rings
029 Equipment Handling Replaced by Tip 62.
030 Stripped Thread Repairs 005
031 Broken Stud Removal 006
032 Column Salvage Guide to Pile Driving Equipment (for column dimensions)
033 Base/Cylinder Column Hole Repair Tip no longer available, due to involved nature of repair.
034 Steam Chest Valve Liners 007
035 Serial Numbers 016
036 Dovetail Repair 018
037 Vari-Cycle Hammers 008
038 Compressed Air Velocity Fuse 009
039 Winter Operation
040 Outboard Bracket Shims 010
041 Valve Flutter
042 Assembly Procedures 011
043 Stud Installation 012
044 Product Bulletin 017
045 Extractor Lubrication See Tip 14 for extractor lubrication recommendations
046 Single Acting Hammer Lubrication Guide to Pile Driving Equipment
047 Super Vulcan Hammer Lubrication
048 DGH 100 Hammer Lubrication
049 DGH 900 Hammer Lubrication
050 Piston & Rod Installation 015
051 Sheet Pile Designations
052 Keys to Cables Factory Advertisement for conversion from keyed hammers to cables; not available online. Click here for information on cable hammers.
053 Serial Numbers 016
054 Product Bulletin 017
055 Steam Chest Valve Liners 007
056 Vari-Cycle Hammers 008
057 Serial Numbers 016
058 Nylon Slide Bars
059 Cushion Pot Dimensions 020
060 Hammer Warranty and Safety
061 Stub Channel Modification
062 Equipment Handling
063 Icing Conditions
064 Proper Hose Connection
065 Sheave Assembly Care
066 Reduced Hammer Energy Guide to Pile Driving Equipment
067 Lubrication 023
068 Hammer Blow Rate
069 Micarta and Aluminum Cushion Material
070 Hydraulic Cylinder Type Packing Upgrade (1 & 0)
071 Serial Numbers (Letter Codes) 016
072 Vari-Cycle II (506 & 512)

Vulcan Onshore Tip #72: Vari-Cycle II (306, 505, 506 & 508, 510, 512 Hammers)

The Vulcan Vari-Cycle II offers all the advantages and ease of use of the original Vari-Cycle with fewer parts and less maintenance.  When maintenance is required, it will be easier and less expensive.  The Vari-Cycle II uses the same principle as the original Vari-Cycle, except the trip shifting cylinder is built into the Open Steam Chest Head Bracket thus reducing the number of parts.  Air is supplied to the movable trip piston to move the trip into either the long stroke or short stroke position.  A detent holds the trip in position when the air supply is removed.  For the 306, 505 & 506 Hammers the Vari-Cycle II is P/N 13711.  For the 508, 510 & 512 Hammers the Vari-Cycle II is P/N 13730.  The Vari-Cycle II is designed to fit the above sizes of Hammers with a Traverse Trip or Vari-Cycle.  On your next new Hammer specify Vari-Cycle II or contact Vulcan to see if your Hammer can be converted.

Note: this was Vulcan’s last Onshore Tip, issued by the Tennessee Corporation. The history behind it, however, isn’t one of Vulcan’s happier adventures.

Vulcan patented the Vari-Cycle–especially important with concrete piles for energy variation–in December 1967. Eleven years later Conmaco patented essentially the device you see above. When Vulcan discovered this device (shortly after Conmaco’s patent publication) and that it infringed on the Vulcan patent, it demanded that Conmaco desist from infringement. Conmaco countered by offering a cross-licensing agreement, allowing Vulcan to make and sell Conmaco’s energy selector. Vulcan refused.

Conmaco did desist from infringement, but when Vulcan’s patent expired (1984) Conmaco was able to make their device without competition from Vulcan. By this time Vulcan began to market its 506 and 512 hammers, and the increased rebound loads from 5′ stroke driving gave the Vari-Cycle reliability problems on these hammers (the device in the larger hammers was more robust.) Adopting “Vari-Cycle II” would have solved this problem, but Vulcan was precluded from doing so until 1995, by which time Vulcan was headed towards merger.

This debacle was an illustration of a point made many years ago:

Agree with thine adversary quickly, while thou art in the way with him…(Matthew 5:25)

Vulcan Onshore Tip #70: Hydraulic Cylinder Type Packing Upgrade (#1 and #0 Hammers)

For many years Vulcan hammers have used woven packing to seal around the piston rod.  Although this type of packing has performed well, packing with longer life would obviously be better for hammer users.

Vulcan now offers a packing that uses a chevron type packing, similar to rod packing used in hydraulic cylinders.  This packing can be inserted into Vulcan hammers without modifying the hammers, providing the gland area of the cylinder is to original factory specifications.

This upgrade is available for Vulcan #1 series Hammers (#1, 06, 306 and 506 hammers, P/N 35366) or Vulcan #0 series hammers (#0, 0R, 08, 010, 012, 508, 510 and 512 hammers, P/N 6214C).  This upgrade will work on Raymond and Conmaco hammers with the same cylinder packing gland as Vulcan’s.

Note: this was a rather late Vulcan adaptation of another Raymond innovation, namely the use of “Chevron” type packing in Vulcan hammers. More information on the Raymond hammers can be found in the Guide to Pile Driving Equipment. This tip was issued by the “Tennessee Corporation.”

Vulcan Onshore Tip #69: Micarta and Aluminum Cushion Material

Micarta (or Conbest) and aluminum cushion material is an excellent cushion material for use in Vulcan Air-Steam Impact Pile Hammers; however, the cushion pot configuration that can be used depends upon the hammer. Below is a breakdown of the various ways in which micarta and aluminum can be used in Vulcan hammers.

Hammers in which micarta and aluminum can be used in both integral ring and capblock follower cushion pots:

  • #2
  • #1
  • 06
  • 106
  • #0
  • 08
  • 0R
  • 010
  • 012
  • 014
  • 016


Hammers in which micarta and aluminum can be used in the capblock follower only (integral ring use not recommended):

  • 505
  • 506
  • 508
  • 510
  • 512
  • 514
  • 516
  • 020
  • 320
  • 030
  • 330
  • 520
  • 530
  • 040
  • 340
  • 540
  • 060
  • 360
  • 560
  • 3100
  • 5100
  • 5150
  • 5250
  • 6300
  • 30C
  • 50C
  • 65C
  • 65CA
  • 80C
  • 85C
  • 100C
  • 140C
  • 200C

This tip supersedes and replaces all previously released information on this subject.

Refer to Vulcan Onshore Tip 59 for information on cushion pot dimensions.

At the top: a diagram showing the cabling of a pipe cap to a Vulcan hammer. The cushion shown was wood. It was a difficulty with this that occasioned this tip.

Vulcan Onshore Tip #68: Hammer Blow Rate

Very frequently users and engineers make the assumption that the output energy of a hammer is somehow related to the number of blows per minute the hammer puts out. Such a notion is mistaken for both Single-Acting and Differential-Acting hammers.

Vulcan specifications for blow rates are computed with the condition of “Normal Stroke, No Set.” This means first that the hammer must be getting a full stroke. This is the foremost method for Single-Acting hammers to determine sufficient energy and should be the main method to determine whether or not a hammer is performing properly.

With Differential-Acting hammers, the pressure at the hammer is the deciding factor. The second part of Vulcan blow rate specifications state that the blow rate is computed with no pile set considered. This includes both consideration of the time it takes to impact the pile and the effects of rebound on the hammer.

The interaction of the pile is an important component in determining the blow rate of a hammer and is extremely variable with driving conditions. Some hammers (such as the single-acting diesels) can have their energies estimated with their blow rates. Because of the action of the air supply, this cannot be done with Vulcan air-steam hammers.

Users who need alternative methods to determine the energy output of the hammer should measure the ram velocity directly or use other accepted methods.

Note: this and Tip 9 deal with a subject that recurs with Vulcan hammers, and has been a source of confusion with some geotechnical engineers.

When Vulcan first introduced the Super Vulcan Differential-Acting hammers, it included with them a chart which correlated the blow rate of the hammer with the output energy. Unfortunately, this chart did not take into consideration either the time of impact or the rebound energy from the pile. Since Vulcan hammers (except for the diesel) were not designed to require rebound to achieve full stroke, the presence of initial velocity after impact seriously affected the blow rate and compromised the usefulness of the charts. Vulcan withdrew the charts and spent many years trying to live down their blowback.

The success of the diesel hammers–and the use of the Saximeter to estimate their rated energy–led some to attempt such a correlation with Vulcan single-acting air/steam hammers. Unfortunately no correlation can be established because of the different nature of the upstroke of these hammers and again because of rebound effects. But the result–confusion–remained.

Although a excessively slow hammer may indicate problems with binding or inadequate lubrication, there are many variables that go into a hammer’s actual blow rate in the field, and thus the factory wisely opted out of any further correlations between blow rate and energy for any of its hammers.

Vulcan Onshore Tip #65: Sheave Assembly Care

Proper care of the sheave assembly is very important, since the weight of the hammer is held by this assembly and a flying sheave or falling hammer could strike a person causing severe injury. Sheaves, axles, pins, keys, nuts, and all lifting points should be continuously checked for worn, loose or missing parts.

Check all cotter, roll and sheave pins for their condition and tightness and replace when worn or broken in service. Make sure that the correct type of pin (cotter or roll) is used with the corresponding type of head sheave. If in doubt, after examining the diagrams at left, consult an authorized dealer or the factory. The sheave pin is both held in place and kept from rotating by the two cotter (or roll) pins on each side.

If the sheave pin needs to be replaced, insert the new sheave pin with the sheave key in the existing hole until the key is firmly against the wall of the cylinder head. Then locate and drill a sheave key hole in the sheave pin. Make the hole the same size as the existing hole and locate it so that both sheave keys are pressed firmly against the walls of the cylinder head. Make sure that when cotter pins are installed the legs are spread so the cotter pin cannot fall out during service.

Roll pins use their internal tension to stay in place. The head sheave bushing should not be removed unless it needs replacement. Consult your Vulcan Onshore Field Service Manual for bushing replacement. If the head sheave needs replacement, a new bushing is included with the new sheave.

Always pull the hammer straight up, not at an angle to its central vertical axis. Pulling the hammer at an angle could pull the sheave pin through the head, disconnecting the hammer and sheave wheel causing both to fall. Avoid the use of spud or H-beam leaders with air-steam hammers of this type.

Use only genuine factory parts with this assembly, as with any other parts of the hammer. The use of nails, welding rod or re-bar to substitute for cotter or roll pins should be avoided

Note: much of the information in this tip is taken from Vulcan’s User’s Guide to Safe Operation, which is featured in the Guide to Pile Driving Equipment.

This is a very important safety bulletin and users of Vulcan hammers should take note and follow its recommendations seriously.

Vulcan Onshore Tip #64: Proper Hose Connection

  • Before connecting air or steam hoses, check the outside of the hose to be sure it is in good, usable condition.
  • Blow air or steam through the hose to be sure no dirt or debris is clogging the inside.
  • Never use an air hose to carry steam! Steam will melt the air hose. Take off all protective tape from the openings of the hammer cylinder.
  • If the openings were not covered, check them to be sure they are clean. It is very important to keep hoses, couplings and openings free of dirt and debris. Doing this will add to the life and safety of the hammer.
  • Air and steam hoses must be safely secured. If they are not, or if they come apart during use, the hoses will whip wildly over a great distance. This can be extremely dangerous and can cause substantial injuries to personnel and property. To lower the risks, all hoses and couplings should be checked at the beginning of each shift and after the driving of each pile.
  • All hoses must be secured by a heavy chain or wire rope (refer to O.S.H.A. Standards 1926.251) attached to an anchor point on the hammer with a shackle, in a way that will support the weight of the hose at the coupling and help stop the jolting motions which happen during operation.
  • There are several good ways of securing hoses:
    • Figure 1 shows the method of running a chain or wire rope from the air/steam inlet extension (A) to the cylinder head bolts at the top of the hammer (6) and securing the air/steam coupling (C) with a separate chain or wire rope.
    • Figure 2 shows the air-steam inlet extension (D) being connected to the lug (E) just above the air/steam inlet, which appears on some hammers, by a chain or wire rope and securing the air/steam coupling (F) with a separate chain or wire rope.
    • Figure 3 shows the air-steam coupling (G) attached directly to the air/steam inlet, without the use of an extension, and secured to lug (H) with a chain or wire rope.

Note: much of the information in this tip is taken from Vulcan’s User’s Guide to Safe Operation, which is featured in the Guide to Pile Driving Equipment.

Vulcan Onshore Tip #63: Icing Conditions

Operation of Pile Hammers and Pile Extractors on compressed air frequently presents problems of ice accumulation in valve assemblies and air passage ports. Icing is a function of temperature and humidity causing erratic equipment operation as, strange as it may seem, icing conditions occur at 85° as well as 32° if conditions are right.

There are several remedies for this problem which will help eliminate the icing condition:

  1. In your air line oiler, dilute your lubricating oil with an equal amount of ethylene glycol.
  2. Install in the air line between the Lubricator and the Hammer a Tanner De-lcer Tank. The Tanner De-lcer atomizes the anti-icing chemical into the airstream to prevent Hammer icing. Tanner gas equipment is available from Tanner Systems, Inc., Sauk Rapids, Minnesota 56379.

Always remember that in subfreezing weather it is essential to preheat the Hammer Cylinder prior to commencing daily operation. This is necessary to eliminate any frozen condensate inside the Cylinder and Valve. It is also to prevent possible cracking of the Cylinder due to thermal shock. During winter operation, it is advisable to be sure that all condensate is expelled from the Lubricator at the end of the shift so that it will not be allowed to freeze thereby plugging the oil suction line. It is also advisable to preheat the Lubricator to assure immediate lubrication when operations are commenced.