Klien Lindner

Ewald Klien and Heinrich Lindner, two engineers of the Royal Saxon State Railways , sought like Klose a solution for a radial

adjustable axle without the fuss of having a swivelling truck with the associated steam tightness problem of the live steam tubes. They developed an axle which looks complicated but is essentially stunningly simple. In fact the axle consist of one solid axle which transfers the drive forces from conventional  drive rods via a ball-and-pinion system to a hollow axle which connects the two wheels. The outer hollow axle has enough room to swivel. Later in their development two such axles were often interconnected to improve riding properties.

The principle of the Klein Lindner hollow axle.
Source http://www.aqpl43.dsl.pipex.com/

The Klien Lindner system remained rather inconspicuous in locomotive history. Undeservedly so, as it was one of the more intelligent solutions to the articulation problem. So much so that it would have been a serious competitor to the Garratt and Mallet forms of articulation. Four fixed axles between two Klien Lindner axles would result in an equivalent of any x-6-x+x-6-x or x-6-6-x arrangement and it would have been perfectly capable of negotiating the same tight curves. Proof of its relative success may well be that the Klien Lindner continued to be built for European railways long after orders for articulated locomotives had dried up. In some cases the Klien Lindner type even actually replaced preceding articulated designs.

In many publications it is mentioned as being hard on maintenance. Admittedly the ball-and-pinion system between the frame plates is a place hard to get by and would have given some difficulty in repair. But the system was fully enclosed making it much less prone to damage and dirt. And never forget that the pivots of other articulating systems were by no means easier to maintain.

Wiki states

"In spite of their relatively simple design Klien-Lindner axles were not widely used. Derailments were common when they were used as leading axles. The axles often caused uneven, jerky running as a result of the resistance forces that arise from this type of Cardan joint, and they were expensive to maintain, something which was not offset by the reduced wear and tear on wheel flanges and rails."

Well, I think this is wrong in many aspects:

• First I think this comparison is applicable only if you compare the Klien Lindner locomotive with a conventional locomotive with the same wheel arrangement. Never forget that a conventional locomotive is always preferable over an articulated whenever possible for simplicity and lesser costs. Articulation is always the second best option. Copared to other forms of articulation however chances are that the KL-system really shines.
• Second L. Wiener describes the Klien Lindner form as a serious competitor to the other types of articulation. Overall the Klien Lindner articulation is much simpler than having pivots taking up much of the locomotive's stress and flexible joints in steam pipes that tend to leak.
• Third is the simple proof of capitalism: the Klien Lindner was built by the thousands even in the relatively small area were it was used. It is very American to think "it was not used here, so it can't be much good". It wás good but its main manufacturer, Sächsische Maschinenfabrik Chemnitz, failed to open up the lucrative export market, so its use was restricted to mainly Germany, Austria and the areas where German manufacturers exported to like Indonesia.
• Fourth is a technical remark. KL was NOT a type of cardan. Moreover a real type of cardan is Shay which is condidered to be very successful by the same Wiki. So let's conclude the Wiki writer as far off.

The Klien-Linder axle as originally conceived

The later developed inteconnection to improve road behaviour.

Many of the locomotives of the German Army were Klien Lindner. Manufacturer photo of Krauss Maffei.
Of this Feldbahn type alone some 2,500 were built, making it the second most numerous articulated locomotive in the world, after the Mallet.

The only surviving artefact of the already poor Dutch articulated history: a Klien Lindner axle of one out of four tramway locomotives of the GSTM, built in 1913 (2) 1923 and 1929. Photo taken by me in 2009, at SHM museum railway.