Collapsible mobile formwork

Slider or15.jpgA unique auxiliary system for construction of new pipelines and replacement of old pipelines by new ones, followed by installation of reinforced concrete rings.


  • The OR-1.5 formwork is designed for operation as a site for the equipment of the MNB-50 machine and for protection of personnel and equipment against soil collapse
  • The inner dimensions of the formwork are designed for installation of reinforced concrete rings for wells, having diameters up to 1.5 m.

The OR-1.5 formwork provides safety of operation and minimal scope of excavations for work at high depth.

Operation principle

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Reinforced concrete rings are installed inside the formwork.

Two hydraulic cylinders, with the load-bearing beam resting on a reinforced concrete ring, are used to lift the formwork belts.

With the formwork belts extension, fill-up soil is used to fill resulting spaces between rings and the formwork.

This is followed by installation of the next ring.

Then the procedure is repeated.


General specifications:

Maximum sinking depth

5 m

Operating temperature range


Maximum diameter of reinforced concrete rings installed

1500 mm

Height of belts:

- the first belt

- subsequent belts

700 mm

800 mm

The hydraulic cylinder for the formwork lifting:

- Rated operating pressure

20 MPa

- Rated pressing force

15,5 tons

- Rod stroke

700 mm

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Using the MNB-50 equipment for a pipeline construction, followed by using the OR-1.5 formwork
for the reinforced concrete well installation: description of stages

Step 1

The first belt of the OR-1.5 formwork is placed on the axis of an old pipeline that must be replaced, or the new pipeline must be constructed, with the pipe-jacking method used for this purpose.

Step 2

Soil excavation is carried out within the formwork gradually sinking it to the designed depth.

Step 3

The MNB-50 equipment is mounted in the OR-1.5 formwork.

The MNB-50 power unit is connected to the hydraulic unit.

Step 4

Works are carried out for pipeline replacement or laying from the OR-1.5 formwork.

After completion of works, the MNB-50 equipment shall be dismantled.

Step 5

Construction of the reinforced concrete well, Ø1500 mm

The first ring is installed in the OR-1.5 formwork.

The load-bearing beam and the hydraulic cylinder are installed to lift one formwork’s belt.

Hydraulic cylinders are connected to the hydraulic unit, the component of the MNB-50 equipment.

Step 6

The load-bearing beam, resting on the reinforced concrete ring, applies force through the set of hydraulic cylinders to press the formwork up from soil by one belt height.

The empty space remaining after lifting the formwork belt is filled by soil, followed by soil compaction.

Then, the procedure is repeated.