Tanker for trenchless drilling operations

Meprozet vacuum tankers have long been a familiar sight across the Polish countryside as units for distributing natural manure. Beyond the fields, the popular “Meprozetkas” are also used in urban areas for liquid‑waste transport, drain cleaning and amenity‑plant maintenance.

For many years Meprozet units have also been adapted to less obvious applications outside the agricultural and municipal sectors. One example is the single‑axle PN‑70 vacuum tanker used in work supporting HDD (horizontal directional drilling) operations. This technology involves trenchless installation of bore paths beneath roads, buildings or bodies of water.

The working fluid in these operations is a bentonite slurry used to create the bore and subsequently to flush spoil from the borehole. The PN‑70 tanker performs a dual role. First, it supplies clean water to the worksite. Filling the tank with liquid may be carried out in two ways: by vacuum using the compressor or directly from a hydrant. On site the water is mixed with bentonite in equipment prepared for that purpose.

At the next stage the vacuum tanker is used to suction the spoil generated during the drilling process. For this purpose the vehicle is fitted with a hydraulically operated suction boom. Spoil discharged into a pre‑made sump is drawn directly into the tanker’s 7 m³ tank. Manoeuvring the boom is aided by a handle mounted on the suction hose and an integrated control panel, which allows the operator to rotate the boom through 270°, move it up and down, and extend the nozzle. For deeper excavations an additional suction hose can be connected.

A hydraulically operated opening rear end plate is essential equipment on the PN‑70. Given the frequent need to wash the tank interior due to the variable nature of the work, this feature greatly simplifies preparation of the vehicle for carrying water after the spoil has been discharged. At the customer's request the tanker has been fitted with a hydraulically driven compressor. With this modification it can be operated by construction machines that typically do not have a PTO shaft. This option is available for vacuum tankers with capacities up to 16 m³.

(source: Technika Komunalna 4/2022, p. 90)