• General Information
  • The Operator's Stand
  • Technical Data
General Information

    The HDD manhole drill TERRA MINI-JET MJS 1600 operates in a manhole. It is controlled from the top via an automatic drill rod lift. The operator stands on top of the road during drilling and backreaming, and not down in the manhole.

    Imagine being able to use existing sewer manholes to lay networks for electricity, gas and water without the need to dig up roadways or front gardens of private properties.

    Swiss producer of trenchless pipe and cable laying equipment TERRA AG has developed such a manhole HDD drill that is able to undertake directional bores from manhole to manhole and from manhole to all near-by homes. At 0.8 m (2.5 ft) depth you can lay telephone cables, at 1.20 m (4”) depth fresh water lines, and at 1.60 m (5 ft) depth gas or power lines.

    This innovative pipe laying method was developed over a 2 year period in close co-operation with the French water supplier SADE.

    The TERRA MINI-JET MJS 1600 is a manhole HDD drill for directional bores in lengths up to 50 m (165 ft) with a minimum turning radius of 15 m (50 ft). The directional bore can be reamed in several steps up to 300 mm (12”) even in hard ground. The TERRA MINI-JET MJS 1600 is equipped with a torque of 1600 Nm (1200 ft.lbs) and thrust and pull back forces of 60 kN (6 tons, 13’200 lbs).

    The MJS 1600 can drill from manholes with an internal diameter of 1.0 m (3.3 ft) and can fit through manhole entrances of just 0.62 m (25”). Where the entrance is smaller than this, the manhole cover frame can be removed. First the drill’s bed frame is lowered into place in the manhole and tightened hydraulically in position, thereafter the manhole drill is lifted vertically through the manhole cover and bolted onto the bed frame. Drilling and back reaming takes place with bentonite drilling fluid pressure of 0-55 bar (0-800 psi) and drilling fluid volumes of 0-38 ltr/min (0-9 gpm). This makes the TERRA MINI-JET MJS 1600 a small but extremely effective horizontal directional drilling (HDD) machine.

The Operator's Stand

    The entire operation of the TERRA MINI-JET MJS 1600 is controlled from the surface where the operator along with the control station, rod magazine and rod lift are positioned.

    There is no requirement to enter the manhole during drilling and back reaming work. The operator inserts a new drill rod into the rod lift. The rod lift transfers it down into the manhole and positions it in the drilling machine.

    The new drill rod is screwed into the last drill rod. Inductive sensors make this operation possible even where the operator does not have a view into the manhole. The rod lift may also be positioned at an angle over the drilling machine where the manhole entrance is not located directly on top of the drilling machine.

Technical Data
Technical Data

*   Depending on ground conditions

Technical specifications can be changed without previous notice.
pullback force
6 to (60 kN)
13'200 lbs (6.6 US tons)
thrust force
6 to (60 kN)
13'200 lbs (6.6 US tons)
driving power
24 kW (33 PS)
24 kW (33 HP)
torque, 1st speed
1600 Nm
1200 ft.lbs
torque, 2nd speed
drill rod rotation speed, 1st speed
0-115 U/min
0-115 rpm
drill rod rotation speed, 2nd speed
drilling fluid volume
38 l/min
10 gpm
maximum drilling fluid pressure
55 bar
800 psi
drilling speed - quick gear
10 m/min
33 ft/min
1.5 m/min
5 ft/min
noise emission in 7 m distance
noise emission at operators ear
pilot bore diameter
Ø 60 - 100 mm
Ø 2.4" - 4"
maximum backream diameter*
Ø 300 mm
Ø 12"
maximum drilling length *
50 m
165 ft
drill rods, length
0.39 m
1.28 ft
drill rods, diameter
Ø 47/30 mm
Ø 1.85"/1.2"
minimum turning radius**
50 ft
Dimensions pit cradle LxWxH
1 x 0.55 x 0.80 m
3.3 x 1.82 x 2.64 ft
Dimensions LxBxH Control Station
1.65 x 0.55 x 2.31 m
5.45 x 1.82 x 7.62 ft
weight of the pit cradle
300 kg
660 lbs
Weight Controll station
170 kg
560 lbs

TERRA AG für Tiefbautechnik - Hauptstrasse 92 - 6260 Reiden - Schweiz - Tel. +41 62 749 10 10 - Fax +41 62 749 10 11 - office@terra-eu.eu