Schwalbe Baugesellschaft mbH & Co. KG

Updated: August 2026 – Before the first machine gets to work at a track worksite, someone stands there with a tripod. What comes out of it is invisible later on – and yet the whole success of the construction depends on it. Schwalbe Baugesellschaft mbH & Co. KG is one of the construction firms with its own railway licence, and this page is devoted to the most invisible part of its trade: track surveying.

What is Schwalbe Baugesellschaft mbH & Co. KG?

Schwalbe Baugesellschaft mbH & Co. KG is a construction firm connected to railway operations. The name follows a classic pattern: a company or family name, plus a designation of purpose and a legal-form suffix. From the suffix “Baugesellschaft” (construction company) comes the classification – the focus lies in construction, not transport.

Details on worksites, vehicles or clients are deliberately left out here: these are variable quantities that change faster than any database can keep up with. What holds true over time is the craft behind it.

Track surveying: the invisible foundation

A track is never lying exactly where it was planned. Traffic load, subsoil, temperature and time shift it – millimetre by millimetre, but constantly. Surveying answers the one question that matters before every correction: where is the track now, and where should it be?

The crucial point here is that without a target value, a machine can only carry forward the existing state. A tamping machine lifts and lines the track relative to what it finds – if no one specifies where the track should actually lie, the result is an evenly tamped track that’s still in the wrong place. That’s exactly why surveying in track construction, often handled by engineering firms such as IGEBA Ingenieurgesellschaft Bahn, matters so much: it supplies the only independent reference in the whole process.

Adding to the difficulty, the reference points themselves can change. Masts settle, structures move, and after major works old fixed points no longer hold. That’s why surveying always includes checking the reference system too – work that stays completely invisible from outside, yet decides whether everything fits together in the end.

The measurements on the track

Measurement	What it describes	Why it matters
Gauge	Distance between the rails	Too narrow or too wide endangers safe wheel running
Cant	Height difference between the two rails on a curve	Offsets centrifugal force, determines the permitted speed
Alignment	Sideways deviation from the target course	Directly affects ride quality and wear
Longitudinal level	Height profile along the track	Dips cause impacts and speed up deterioration
Twist	Change in cant over a stretch	Excessive values load bogies unevenly

Comparably positioned companies can be found under GBM Gleisbau Maas, Hans Strube Gleisbau, Hochbau, Tiefbau and Deutsche Gleisbau Material Transport.

Vehicles used for surveying and track alignment

Surveying happens partly on foot with instruments, partly with vehicles that generate target values directly for the machines that follow. After that, heavy machines take over the actual correction.

For setting-out and measuring in, there’s the Plasser & Theurer EM-SAT 120, whose task lies precisely in this preparation. The subsequent correction is carried out by tamping machines such as the Plasser & Theurer 09-4X Dynamic. For work beside the track, road-rail machines such as the Atlas 1604 ZW are used. The guide to identifying classes shows how to systematically classify such vehicles.

How to recognise surveying work

Anyone regularly travelling the same route can even place these signs in time: markings and survey points appear first, then material deliveries at access points follow, and finally the machines move in. Weeks can pass between the first and last step – a period in which it’s excellent to document how a construction project takes shape.

Surveying is the quietest part of a worksite – and often happens weeks before the actual construction. Anyone who knows the signs sees a worksite coming before it’s even set up.

How to keep such observations organised long-term is described in the guide on keeping a sightings log.

Common mix-ups

Because surveying work is quiet and unobtrusive, it’s regularly misread – sometimes as a worksite, sometimes as a fault, sometimes not noticed at all. This list sorts out the most common cases.

• Surveying and route measurement runs – this is about the worksite on the ground, not measuring trips across the whole network.
• Marking and graffiti – coloured marks on sleepers and rails are work instructions, not vandalism.
• Construction firm and infrastructure manager – the firm works under contract, the route doesn’t belong to it.
• Tripod equals camera – surveying instruments look like cameras from a distance.
• Quiet worksite equals a break – preparation and surveying often run long before a machine arrives.

Conclusion

From the outside, track construction looks like heavy machinery and lots of ballast. In fact, every worksite begins and ends with numbers: the actual position beforehand, the target position during, and the verification afterwards. Anyone who knows this sees, in a tripod beside the track, the start of an entire construction project.