Vulcan Vari-Cycle (Stroke Control) is available for all Vulcan Single Acting Hammers having a cylinder which has as an integrally cast pad part thereof the necessary mounting pads for installation of the Vari-Cycle equipment. Shown in the table below are the first Serial Number and date of those hammers (by size) having Vari-Cycle factory installed or mounting pads for field retrofit.
| Hammer Size | Serial Numbers and Date | |
| Onshore Hammers | Offshore Hammers | |
| #1 | See Note 1 | – |
| 06 | See Note 2 | – |
| 08 | GB-8095/10-27-72 | – |
| 010 | GB-8100/11-2-72 | – |
| 014 | FI-6250/5-13-69 | – |
| 016 | FI-6515/12-19-69 | FH-5500/2-1-68 |
| 020 | FG-5190/12-19-69 | FH-5530/2-15-68 |
| 030 | – | FH-5645/4-19-68 |
| 040 | – | FG-5330/12-8-67 |
| 340 | – | GC-8245/2-12-73 |
| 540 | – | GD-8800/5-22-74 |
| 060 | – | FH-5555/6-15-68 |
| 360 | – | GD-9025/7-19-74 |
| 560 | – | GC-8445/7-18-73 |
| 3100 | – | GE-9450/6-11-75 |
All Hammers having Serial Numbers subsequent to those above are configured as to accommodate Vari-Cycle.
Note 1 — The following Size #1 Hammers are equipped with mounting pads for Vari-Cycle:
GC-8455/GC-8555/GC-8595/GC-8715/GC-8765
Vari-Cycle mounting pads on this size Hammer were discontinued 8-23-74.
Note 2 — The following Size 06 Hammers are equipped with mounting pads for Vari-Cycle:
GD-8750/GD-8740/GD-8825/GD-8605/GC-8605/GC-8685
Van-Cycle mounting pads on this size Hammer were discontinued 7-24-74
Note: This tip obviously does not cover the hammers later than the mid-1970’s, especially the onshore 5′ stroke hammers. Their situation is complicated; you can contact us to ask questions about this. All of the Vulcan 5100, 5110, 5150 and 6300 hammers can accommodate Vari-Cycle and indeed virtually all offshore hammers from the 1970’s onward were either equipped with Vari-Cycle or Traverse Trip. Below are some photos of the Vari-Cycle mechanism.
vulcanhammer.info 
5 thoughts on “Vulcan Offshore Tip #8: Vari-Cycle Hammers”