DIEMA DVL 150

Updated: August 2026 – A small vehicle, two axles, a short bonnet, a cab for one person: locomotives like the DIEMA DVL 150 are the quiet workers of railway operation. They never run to a timetable, rarely carry a class number, and are precisely for that reason a challenge for anyone who wants to identify vehicles properly. This page shows you how to go about it.

What is behind the DIEMA DVL 150?

DIEMA is short for the Diepholzer Maschinenfabrik Fritz Schöttler, a manufacturer of small diesel locomotives based in Lower Saxony. It built vehicles for industrial, works, light and peat railways – in other words for operations that have their own track but do not need state-railway vehicles. Many of these machines have survived at light-railway collections such as the Frankfurt Light Railway Museum. DVL 150 is a works type designation, not a class: the letters denote the design, the number a power class.

That is an important difference. With a state-railway class, the number gives you an entire vehicle series as well. With a manufacturer’s type, you get a design concept that can be built out differently depending on the order – a different engine, a different gearbox, a different body. That is why, on works locomotives, the builder’s plate matters more than any type designation.

How to identify works and small locomotives

Identifying a small locomotive works differently from a main-line locomotive. Body shape and number are not enough – you need the manufacturer’s details on the vehicle itself.

The general order in which to work through features is set out in the guide to identifying rolling-stock classes. Comparable small-locomotive types from other manufacturers can be found in the Schöma CFL-200 DR and the LKM Ns 2.

Placing it: why small locomotives are their own category

In the twelve-digit vehicle number, the first two digits separate the vehicle types. For diesel locomotives there are two groups, and the difference is exactly that between main line and shunting duty.

Feature	Small/shunting locomotive (98)	Diesel main-line locomotive (92)
Typical number of axles	two to three	four to six
Maximum speed	low	medium to high
Area of operation	works, siding and station tracks	open line on the network
Designation	often a manufacturer’s type instead of a class	usually a class number
Reliable identifier	builder’s plate and works number	operating and UIC number

This split also explains why you can barely find reliable inventory lists for small locomotives: vehicles that only run on private track simply do not appear in public registers. How to systematically build up your own finds regardless is shown in the article on building a photo archive for spotters.

Spotting: close by, but never on the site

Small locomotives often stand within sight but are almost always on private property. That is exactly where the challenge lies. The exception is heritage and light-railway operations such as the Dampf-Kleinbahn Mühlenstroth, where such vehicles stand freely accessible on running days.

• Viewpoint first. Public road, pavement, bridge – from there, everything you can see is allowed. A works site is not.
• A longer focal length instead of getting closer. Fences and distance can be solved photographically, not legally.
• Details are worth it. Builder’s plate, coupling, frame shape and buffers are the real information on small locomotives.
• Names rather than numbers. Many works locomotives carry their own names or internal numbers. Both belong in the sighting log.
• Note the condition. Operational, stored, or a monument? This changes quickly with this group of vehicles.

Which distances apply at the track and why they are not a matter of judgement is covered in the article on safety distances at the track.

Why works locomotives so often get counted twice

Anyone collecting small locomotives sooner or later runs into a typical problem: the same vehicle turns up several times in lists – once under the manufacturer’s type, once under a power rating, once under the name of the operation it belongs to. That is not sloppiness, but a consequence of there never having been a uniform naming system for this group of vehicles.

Three naming paths run in parallel:

• Works type, as assigned by the manufacturer – for DIEMA that means a letter code plus a number.
• Power rating, as dealers and operators like to use it when the works type is not known.
• Operating number or own name, as assigned by the respective operation and changed again on sale.

Only one piece of information stays stable through all these changes: the works number. It appears on the builder’s plate, never changes, and identifies the vehicle unambiguously. That makes it, for works locomotives, what the class number is for the state railway – only more reliable.

A comparable small locomotive from another manufacturer, where the same logic applies, is the Gmeinder D 25 B. Put both pages side by side and you can see the pattern: different works, the same design concept, the same identification problem – and the same solution via the plate on the frame.

Common mix-ups

Verdict

With the DIEMA DVL 150, the hurdle is not the technology but the state of the information. Reliable public data on works and small locomotives is rare, but what you do have is a vehicle standing right in front of you, carrying everything you need: number of axles, body shape, coupling – and above all the builder’s plate. Anyone who consistently logs these features is building the very database that otherwise does not exist anywhere.