Tunnel lubrication plays a pivotal role in the success of all trenchless methods while improving the performance of tunneling, pipe jacking, microtunneling, guided boring, and horizontal directional drilling systems. The right lubrication system not only reduces frictional forces along the pipe string, but today’s advanced systems also incorporate variable flows, pressures, and additional pumping strategies that enhance material flow and maximize the mechanical properties of the trenchless equipment design.
A common misconception in the trenchless industry is that the lubricant, often referred to as bentonite slurry, coats the jacking pipe and makes it slippery. While a well‐designed mixture will seem to have these results, lubrication mixtures are formulated based on the site’s geology, trenchless equipment design, and lubrication system capacity to maintain the open annulus created between the cutter head and the jacking pipe. In certain ground conditions, the use of an improper mixture or misapplication can lead to increased jacking loads or even failure.
High Pressure Lubrication Systems
Below is a general guideline, given as a starting point for your next project. We always recommend consulting with a mud engineer for an on‐site evaluation of your geology.
|Ground Type||Ground Conditions||Reactivity||Lubrication Mix|
|Coarse Soils||Sands, Gravel, Rock||Non-Reactive. Does not swell. Does not get sticky.||Water (pH-controlled), Bentonite. Addition of PAC or Xantham Gum may be required|
|Fine Soils||Clay & Shale||Reactive. Tendency to swell with water. Can get sticky.||Water (pH-controlled), Bentonite with clay inhibitor. Surfactant to reduce stickiness|
|Mixed Soils||Variable||Ground may react differently depending on the ratio of coarse/fine material||Mixture of Bentonite, Flocculant, or clay Inhibitor|
Akkerman produces a complete family of lubrication/mud pumps suited for the trenchless industry’s rigorous demands. High‐pressure lubrication pumps are the perfect complement to extend distances during pilot tube installations. These same systems are versatile and mobile for any trenchless project, like pipe jacking, microtunneling, auger boring, directional drilling, and vertical drilling applications, to name a few.
I have been working in the underground construction for the past 40 years. In the last 25 years I’ve been involved with all kinds of tunneling operations. Hand mine tunnels using jacking equipment, wood box tunnels dug by hand. But my favorite type of tunneling is MTBM’s. I have been working with and around Akkerman tunnel machines from 120” wheeled machines all the way down to the 48” SC tunnel machine. We’ve done successful runs in ranges from 200’ to 800’ with no problems. In all my years of tunneling we have never had a failure of equipment to cause us any down time. When we have had issues with mechanical parts or service needed Akkerman can usually get you the parts pretty quickly and technicians can get on a plane and help you out also. The team at Akkerman is always ready to answer any questions or problems you may have. They can help you decide on what equipment might work best for your particular job needs. I’ve also been involved with the GBM equipment we have run 32” PCH installing 30” Hobas pipe and also 44” PCH installing 42” Hobas pipe. We have had great success with GBM runs up to 500’ in length. Our last purchase was a new 5200 series jacking frame and 60” series 2 MTBM. We chose Akkerman for this equipment for our past experience and the fact they are made in the USA and can service us quickly. It truly has been great working with Akkerman.