Vulcan’s Blow Count Specifications

The durability and longevity of Vulcan pile hammer is something that is seldom replicated in just about any other manufactured product.  Since pile driving is self-destructive on the equipment, this is a remarkable achievement, but it should be tempered by the fact that it’s possible to render a Vulcan hammer inoperable by the way it’s used.  There are many things that can make this happen–inadequate or nonexistent hammer cushion material or lubrication to mention two–but the one thing that Vulcan decided to include in its warranty was the blow count specification.

Recording the blow count–the number of hammer blows per inch, foot or metre of pile advance–is virtually universal on pile driving jobs.  The dynamic formulae basically translated blow count into pile capacity.  While anyone familiar with pile dynamics understands that blow count is a crude measure of the response of a pile to impact, including a blow count specification is a good first measure of both the advance of the hammer and also how much energy is being returned to the hammer, which is a case of hammer damage.

BLOWCNT
Blow count-resistance graph, developed by Vulcan in the early 1990’s as part of its effort to educate state and federal agencies on the basics of pile driving. As the blow count increases, the amount of SRD (soil resistance to driving) increases, but at a progressively slower rate. This indicates that simply increasing the blow count is a “diminishing returns” proposition, destructive for hammer and pile alike.

High blow counts indicate that more and more of the energy was going back into the hammer rather than into the pile, thus increasing the danger of hammer damage.  They also indicate that pile top stresses increase with higher blow counts, as the movement of the pile to mitigate the maximum impact force decreases.  Thus high blow counts just to get the pile to tip elevation without considering changes in hammer or basic drivability considerations is a losing proposition.

Starting in the late 1970’s, Vulcan voided the warranty on its hammers if the blow count exceeded 120 blows/foot.  It’s interesting to note that Vulcan never made its specification in blows/inch.  This was true for its onshore hammers; however, for its offshore hammers it was forced by circumstance to increase the hammer refusal criterion as follows:

BLOW COUNT SPECIFICATION 1

Vulcan hammers are designed to withstand a continuous driving resistance of 120 blows/foot (400 blows/meter). In addition to this, Vulcan hammers will withstand refusal driving resistance of 300 blows/foot (1000 blows/meter) for five (5) consecutive feet (1500mm) of penetration. Any resistances experienced in excess of these are beyond rated capacity and will void the warranty. This definition is not an exclusive definition of excess of rated capacity and other criteria may apply.

1 Specification applies to all Vulcan offshore hammers, not just those listed in this catalog.

This was drawn from the API RP 2A specification, which was discussed relative to pile stick-up.  An elevated refusal blow count specification was justified by two things.  First, the offshore hammers were more robustly built than the Warrington-Vulcan hammers which made the company famous, as they were derived from the Super-Vulcan hammers.  Second, the remoteness of offshore job sites made high blow counts a necessity, as bringing a larger hammer to the job was frequently impractical.  (Improved methods of drivability predictability lessened the possibility of this happening.)

Blow count limiting warranty specifications are not an absolute method to prevent hammer abuse, but they’re a good start, and Vulcan used them to the advantage of itself, its end users and the owners of the projects where Vulcan hammers were used.

Vulcan Offshore Tips: Introduction and Index

More details on the repair, maintenance and operation of Vulcan hammers can be found in the Vulcanhammer.info Guide to Pile Driving Equipment.

Tip Number

Title
(click on title for tip you want to see)

Corresponds to Onshore Tip

001 Head Gasket/Single Acting Hammer 1
002 Ram Keys Too Tight 8
003 Tightening the Packing Gland 10
004 Removing Broken Ram Point 24
005 Stripped Thread Repairs 30
006 Broken Stud Removal 31
007 Steam Chest Valve Liners 34, 55
008 Vari-Cycle Hammers 37, 56
009 Compressed Air Velocity Fuse 38
010 Outboard Bracket Shims 40
011 Assembly Procedures (Fastener Torque) 42
012 Stud Installation (Tap-End Studs) 43
013 Trouble Shooting 12
014 Bushing Replacement 27
015 Piston & Rod Installation 50
016 Serial Numbers 35, 52, 57
017 Product Bulletin 44, 54
018 Dovetail Repair 36
019 Bar and Suspension Head Dimensions
020 Cushion Pot Dimensions 59
021 Pipe Cap Dimensions
022 Hammer Center of Gravity
023 Lubrication 5, 67
024 Replacing the Packing
025 Slide Bar Gripper Modification

Your Vulcan Offshore Pile Hammers will give you better and more consistent service if they receive good maintenance on a continuing basis.

These initial Vulcan Offshore Tips and subsequent issues should provide valuable assistance in repairing and maintaining your hammers. Consult them frequently.

Keep downtime to the minimum.

Background

The exhortation above graced the original table of contents for the Vulcan Offshore Tips. The tips were the offshore counterpart of the more extensive Onshore Tips.

The idea of the Vulcan Tips was to provide practical maintenance information on a periodic basis to the end users of Vulcan equipment. A great deal of information was conveyed with the tips; some of it was later incorporated into the Vulcan Field Service Manuals.

The Offshore Tips were first issued in the mid 1970’s; the last tip mailed out was in 1985 and the last one to be prepared was in 1993. The graphical quality of the tips was, to say the least, elementary; in putting these tips on the Web, we attempted to retain this quality in order to give you a feel for the original. We have also made every attempt to replicate the information in the Tips. However, when we feel it is helpful, we have added notes at the bottom of the tips in italics concerning subsequent developments that are important in understanding the contents of the tips.

“Take a tip from Jess Perry…”

The caricature on the left side of our banner above also appeared with the original Offshore Tips. However, the character depicted was very real; Jesse H. Perry was Vulcan’s Manager of Engineering Services from the mid-1960’s until his sudden death in July 1983. As has been the case for nearly twenty years, this Web version of the Vulcan Offshore Tips is dedicated to his memory.

To be a successful field service man requires a unique combination of personal and technical skills. A Vulcan field service representative had to:

  • Be very knowledgeable about the equipment and its application;
  • Be willing to travel extensively, frequently in unglamorous places (oil is always found in places like this) and be gone for extended periods;
  • Balance the best interest of his customer (the offshore contractor,) the owner (the oil company) and his employer (Vulcan.)

No individual that ever held any field service position at Vulcan was as capable of doing all of this as Jesse Perry, and this webmaster still counts it a privilege to have worked with Jesse both in the office and the field.

Vulcan Offshore Tip #25: Slide Bar Gripper Modification

Many Vulcan hammer users have expressed interest in a method other than the pipe plug retainers to keep the slide bar gripper wedges in place on Vulcan’s largest hammers. Above such a method is shown; the pipe plugs being removed and the bolt and nut arrangement installed as shown above. For users of metric parts, a M20 X 450mm long bolt can be used and a 22mm hole can be drilled through the gripper and the wedges.

Note: Originally dated 8 November 1993. This tip was never “issued” in the sense that it was mailed out to a list of customers, but was sent to them upon demand. It is interesting to note that, exactly three years after the date this tip was issued, the transaction that passed Vulcan from the Warrington family to Cari Capital Company took place.

Vulcan Offshore Tip #24: Replacing the Packing

When replacing the packing, the pieces closes to the piston rod will be the ARAMID FIBER (yellow in color) with the remainder being the woven FIBERGLASS.

Many Pile Hammer mechanics have a tendency to tighten the Packing Gland too tight. A little steam or air leaking through the Packing is not objectionable. The oil mixed with the escaping air or steam will lubricate the Packing and Piston rod.

Note: Tip date 1 April 1985. This was the last of the Vulcan Offshore Tips actually “issued” but one additional was prepared and sent selectively.  This is an update to Offshore Tip #3.

Vulcan Offshore Tip #23: Lubrication

Below are the lubrication specifications for the Vulcan offshore pile hammers. Above is a hammer diagram showing the locations of lubricant applications.

APPLICATION POINT Lube Type Oil Viscosity Flash Point (Min.) Other Requirements
SUS, 212° F cSt, 100°C Deg. F Deg. C
  1. Cylinder and Base Jaws.
  2. Trip Faces.
  3. Slide Bar.
  4. Slide Bar Dovetail.
  5. Columns/Ram Grease fittings*
  6. Columns/Exposed Surfaces*
  7. Hydra/Nuts
NLGI EP2 Grease 70-100 13-20 450 235
  • Permitted Thickners
    • Lithium 12 Hydroxy-Stearate
    • Lithium Complex
    • Calcium Complex
    • Polyurea
  • MoS2 Anti-Wear Additive
  • Anti-Rust Additive
  1. Relief Ports (Steam Opr.)
  2. Steam Line Oiler
Steam Cylinder Oil
AGMA 8
160-190 34-41 550 290 10% Tallow or Lard Content
  1. Relief Ports (Air Opr.)
  2. Air Line Oiler
Air Compressor Oil
AGMA 1
40-50 40-50 400 200 Anti-Oxidant
  1. Outboard Bearing
  2. Open Steam Chest Bearing
Gear Oil
AGMA 5 EP
80-105 80-105 400 200

It is important to keep your Vulcan hammer properly lubricated to insure the maximum possible hammer life and driving performance.

Also, for the threads of the cable fittings. use an an anti-seize compound to prevent galIing and freezing of the threads.

*NLGI EP2 greases will vary widely in the results for this application. Another alternative to this is a heavy open gear lubricant with MoS2 anti-wear additive. This should be applied directly to the exposed columns.

Note: Tip dated 1 August 1980. Another presentation of this data is contained in the Onshore Field Service Manual. Click here for more details.

Vulcan Offshore Tip #22: Hammer Center of Gravity

Below are listed the center axial centers of gravity for Vulcan Offshore Hammers.

offtip22
HAMMER SIZE CENTER OF GRAVITY
Inches
020 73.0
030 84.0
340 93.0
530 99.0
360 94.0
540 108.0
3100 118.0
560 109.0
5100 131.0
5150 124.0
4250 129.0
6300 140.0

offtip22a

Note: Tip dated 1 August 1980. Some Vulcan sales people also carried the chart below. Keep in mind that the weights for the pipe cap are probably before the “Light Weight High Strength” pipe caps begun in the early 1980’s. The hammer distance from the top and the leader weights are also probably conditioned by the Vulcan leader design before the “Light Weight Pipe Construction” leaders started in the early 1980’s. The chart below was intended to be more informative to those who were doing calculations for the “pipe stickup” requirements of API RP2A, which was the main purpose of the center of gravity data in the first place.

  • W1 = Weight of hammer, striking parts, and typical pile cap (lbs.)
  • D1 = Distance from top of pile to center of gravity of hammer (ft.)
  • W2 = Weight of leaders or guide cages (lbs.)
  • D2 = Distance from bottom of bell to center of gravity of leaders (ft.)
Hammer W1 D1 W2 D2
016 Steam 42940 5.1 16850 20.0
020 Steam 53785 6.7 16850 20.0
030 Steam 65410 8.4 16850 20.0
340 Steam 129440 8.0 30000 24.1
530 Steam (54″ Jaws) 67860 8.5 16850 20.0
530 Steam (80″ Jaws) 89680 6.7 29700 24.1
360 Steam 167430 8.7 64750 25.8
540 Steam 135780 8.0 33700 24.1
560 Steam 179960 8.8 68000 25.8
5100 Steam 288500 11.1 110000 31.5
5150 Steam 351380 11.6 110000 31.5
5250 Steam 558000 9.8 137000 35.0
6300 Steam 712000 13.0 137000 35.0
200C Steam 52315 7.8 15500 20.0

Vulcan Offshore Tip #21: Pipe Cap Dimensions

In addition to the cushion block size, another important input to the wave equation analysis is the size of the pipe cap (or anvil) block. Below are the basic dimensions for the pipe caps along with the depth of the steps.

HAMMER SIZE

A BDIA. C D E GR.
010 8 32 40 10 1/4 3
014, 016 10 39 53 3/4 10 1/4 3 29
016, 020, 030, 200C, 530 15 51 53 3/4 10 1/4 3 29
040, 340, 530, 540 18 1/2 75 80 14 4 6
060, 360, 560, 3100, 5110 24 75 87 1/2 18 1/4 4
5100 16 1/2 102 119 1/2 22 4
5150 19 1/2 102 119 1/2 22 4
126 143 1/2 22 4
6300 28 1/2 126 143 1/2 22 4

All dimensions in inches unless otherwise noted.

offtip21

Note: Tip dated 1 September 1980. Dimensions in italics are for hammers introduced after that date. Subsequent to this Vulcan introduced its line of “Light Weight High Strength” pipe caps. The dimensions such as “A” were reduced and others such as “F” and “G” were eliminated altogether. It is important to determine whether the pipe cap being looked at conforms to the above dimensions or not. Also, many of Vulcan’s customers manufactured their own pipe caps, which may or may not conform to the dimensions shown in this tip.

pipe-cap-gh-830
Classic Vulcan offshore pipe cap; this photo is from 1978. Vulcan preferred a “beehive” or “female” cap. The advantage was the more direct transfer of force; the disadvantage is that the steps had to be custom machined (or shimmed) to the pipe inside diameter. Peeking out above the cone is the top plate; the welding bottles are actually behind the cap. Below the top plate the cushion material was placed.

Vulcan’s choice of pipe cap design deserves some explanation. At the top 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 Offshore Tip #20: Cushion Pot Dimensions

Frequently in the course of designing a foundation, the dimensions of the cushion block are necessary for purposes of computing its stiffness for the wave equation analysis. Below are the cushion pot dimensions for our air/steam hammers:

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Hammer A B C D E F
2, 30C 10 1/4 7 1 1/2
1, 06, 50C, 65C, 505, 506, 106 11 1/4 7 3/8 1 1/2 3 18 1/2 3
0, 08, 0R, 010, 010 Offshore, 012, 508, 510, 512, 65CA, 80C, 85C, 100C 13 3/4 8 1/2 2 3 18 1/2 3
014, 016, 140C 17 1/4 7 2 4 18 1/2 4
020 Onshore, 030 Onshore, 200C Onshore 19 1/2 7 2 6 3/4 25 5
020 Offshore, 030 Offshore, 520, 530, 535, 200C Offshore 22 1/2 5 4 6 1/4 25 5
040, 340 25 1/4 9 1/2 4 12 1/4 26 1/2 5
060, 360 27 1/4 6 1/2 6 12 1/2 31 6
540 27 1/4 7 1/2 6 12 1/2 25 6
560, 5110 31 1/4 7 1/2 6 12 1/2 31 6
3100 36 1/4 7 1/2 6 12 1/2 25 6
5100 41 1/4 7 1/2 6 6 40 3
5150 45 1/4 9 1/2 6 6 40 3
4250 66 10 1/2 8
6300 71 1/4 10 1/2 8

All dimensions in inches.

Note: Tip date 1 August 1980. Hammers and accessory dimensions have been added to the list to include onshore hammers and offshore hammers developed after that date. All additions are shown in italics.

Following is an explanation of how these configurations actually look on Vulcan hammers.

Vulcan Offshore Tip #19: Bar and Suspension Head Dimensions

In order to provide the suspension cables for a Vulcan Offshore Hammer, the following dimensional data are provided for bar and suspension heads.

offtip19

HAMMER

DIMENSION (SEE FIGURE), INCHES

Bar and Suspension Heads

Suspension Head Only

A B C D E F G
010 3 1/4> 4 4 1/2 7
014/016/140C 4 1/4 5 5 7 1/2
020/030/530/200C 4 1/2 6 6 7 1/2 2 1/8 3 21/2
040/340/540/400C 5 1/2 7 8 9 2 7/8 5 2 7/8
060/360/560/600C 6 1/2 8 7 5/8 10 2 7/8 6 3 1/2
3100/5100 6 1/2 8 7 3/8 10 4 6 3 1/2
5150 7 7 1/2 9 3/4 10 4 7/8 7 1/2 5
6300 8 10 6 1/4 12 5 6 1/2 4 1/2

Note: The suspension head dimensions for the 520 and 535 are identical to the 020. The dimensions for the 5110 is the same as the 060.  Some examples of the use of these are shown below.

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Vulcan Offshore Tip #18: Dovetail Repair

As your Vulcan Offshore Hammers grow older, it is unavoidable that wear occurs in the Dovetail Guide in the Cylinder that guides and retains the slide bar. Excessive wear in this Dovetail Guide can cause damage to not only the Slide Bar but the Trip and the Valve Stem. Where replaceable dovetail inserts are not standard equipment, the following methods of dovetail repair are recommended- Two repair methods are shown above in 1 & 2 depending on wear conditions in the Dovetail.

Repair method I is recommended when the majority of the wear has taken place on the angular surface of the Dovetail and the bottom flat surface does not require repair. The steps to follow for repair are as follows:

  1. Remove by machining worn dovetail surfaces as shown at A & B, Illustration #1.
  2. Manufacture BRONZE replacement gibs of appropriate size. as shown at C, Illustration #2. SAE 660 Bronze is recommended.
  3. Drill and tap Cylinder for cap screws as shown at D, Illustration #2.
  4. After installation of gibs, it is necessary to centerpunch each cap screw in at least three locations on its periphery to prevent backout as shown at E, Illustration #2.

Repair method 2 is recommended when wear has taken place on all three Dovetail surfaces (bottom and two angular sides). The steps to follow for repair are as follows:

    1. Remove by machining 1/16″ of surface metal on all three surfaces as shown at A, Illustration #3. This is to remove work hardened surfaces from worn areas.
    2. Build up all three surfaces with sufficient material to allow for remachining by either of the following methods:
      • Arc brazing with Bronze rod.
      • Arc welding with 100% Nickel rod.
      • Gas brazing and gas welding are not recommended for cast iron material in this area of the cylinder.
    3. Remachine built up Dovetail area back to original factory dimensions as at B, Illustration #4.

IMPORTANT

When restoring Slide Bar Dovetails, it is absolutely essential that restored surfaces conform to original dimensional relationships with the center lines of the cylinder and Valve Chest. Contact factory for specific dimensions before proceeding.

Note: Method #1 seldom addresses real dovetail repair problems because the dovetail seldom wears only on the angled surfaces, but on the back as well. A more satisfactory solution to this problem would be to use the removable and replaceable Slide Bar Guide Block as Raymond used, but Vulcan never adopted this solution on its hammers.