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Ordnance survey in railway construction

2026-08-03 LDA 91 Christian Fehn (DE) (3).jpg

LDA 91 for the Rhine corridor renovation

Between Troisdorf and Wiesbaden, a section of the railway line on the right bank of the Rhine will undergo extensive modernization in 2026. Before the construction of the protective structures, the subsoil in the designated work areas will be examined for possible wartime relics.

Christian Fehn is carrying out the necessary exploratory drilling as a subcontractor. The LDA 91 is being used in combination with the KAISER S12 walking excavator. Its low weight, modular design, and large working range facilitate work in challenging and difficult-to-access sections of the route.

How the exploratory drilling is carried out

Drilling in a defined test grid

The subsoil is being examined for unexploded ordnance using special 120 mm diameter rotary augers. Depending on the location, the boreholes reach depths of 5.5 to 7.0 meters. The predefined grid provides the basis for a systematic inspection of the planned construction areas.

Targeted examination of suspicious areas

If drilling progress is not possible at certain depths, the area is examined more closely using a probe and, if necessary, ordnance disposal is carried out.

Why LDA 91?

Low weight for smaller carrier machines

Depending on the set-up, the LDA 91 weighs between 770 and 1,150 kg and is designed for carrier machines from 9 t upwards. This facilitates its use in situations where space, access, and load capacity limit the use of other equipment.

Mobility for changing drilling positions

The drill feed can be rotated 360°. A modular tilt module allows for up to 90° of inclination, while 1,000 mm of feed shift supports precise positioning at the drilling point. The optimized walking foot is designed for operation with a walking excavator.

Drilling drive and control

The EURODRILL RH2X delivers a torque of 2,120 Nm and combines it with a high-frequency impact mechanism delivering up to 4,000 blows per minute. The radio remote control allows for remote operation of the drilling attachment and provides an overview of the carrier machine’s movements.

Learn more about the LDA 91

Frequently asked questions about the LDA 91

Why is LDA 91 suitable for hard-to-reach areas?

Their low operating weight, modular design, swivel and tilt range, and carriage displacement support flexible and precise positioning at the drilling point.