The International Steam Pages

Semi-articulated Locomotives Part 1

Click here for the introduction to Articulated Steam Locomotives of the World.

Wiener classified Semi-Articulated Steam Locomotives in two parts:

1. Semi-articulated Locomotives with a single engine and two driven trucks eg Luttermöllers and Klien-Lindner axle locomotives

2. Semi-articulated Locomotives with two engines and two sets of driving wheels eg Mallets

A. Semi-articulated Locomotives using chains

Wiener records that early experiments were not perpetuated.

B. Semi-articulated Locomotives using gears

Early experiments with gears (such as the true Engerth locomotive which had an 'engine' under the tender) failed to produce a successful locomotive. 

The locomotive 'Genf' normally based at the Swiss Transport Museum in Lucerne was designed and built for Engerth himself. It is universally called after him although Wiener would have called it a 'modified Engerth', as the boiler and firebox weight is part supported by the tender which can still swivel under it, it has no gears. There are other so-called Engerth locomotives and these are covered elsewhere in these pages under Stütz tenders - they actually work in the opposite sense to this locomotive. This picture comes from and may not be reproduced except under the conditions stated on that page.

However, the chief engineer of Orenstein and Koppel, Gustav Luttermöller, perfected a system in which the outer axles were connected not by rods but by an internal gear train. Typically these were 0-10-0s and this allowed axles to have much greater 'play' which allowed them to get round curves with which a conventional locomotive would struggle. This is taken from the OK book - see Bibliography.

Luttermöller locomotives could be built with both inside and outside frames. Although the pictures below are some years old, all these examples survived active in sugar mills in Java, Indonesia in 2009. Lucky enthusiasts like me saw similar locomotives working in the oil palm estates of North Sumatra but they all finished by 1993. Externally Luttermöller locomotives appear to be 2-6-2s but all the wheels are necessarily the same size and when such a locomotive slips, it is immediately clear that the end axles are connected, this is especially so for those with inside frames.

For a YouTube video that shows this see

#6 is a 700mm gauge inside framed Luttermöller at Pagottan (near Madiun, Java, Indonesia) at work in 2004


This is a close up of sister locomotive #7 taken out of season in 2008.

This is 750mm gauge outside framed Luttermöller Tasikmadu VI near Solo (Java, Indonesia) in 2002.

Similar locomotives were built by Henschel and 700mm gauge #12 survived active at Rejosari near Madiun (Java, Indonesia) until recently, although I confess that this picture was taken in 1975!

A rare Jung 'semi-Lüttermoller' 0-8-0T (8301/1939) is on display in front of the RSVG bus depot west of Hennef (Sieg) in the Reutherstrasse in Stossdorf in Rhein-Pfalz, Germany. Only the first and second axles are joined by gears. These are Thomas Kautzor's pictures (added 21st June 2015).

C. Semi-articulated Locomotives using reciprocating mechanisms

Wiener lists no less than 24 such systems in 5 different groups, probably no more than 5 systems were of any real significance...

Transmission by rods located on the axis of the locomotive - a non starter

Convergent Axles coupled by Oscillating Levers

Of the four systems listed, only the Hagans system saw the light of day - see Such locomotives had two sets of wheels, the forward set were conventional. The rear set was driven by a set of rods and oscillating levers, which meant that the rear bogie could be allowed to move laterally. Gölsdorf axles could do the job just as well and the system was rapidly consigned to the history books. No such locomotives survive.

Convergent Axles coupled through Driven Countershafts

Of the eight systems listed, only the Fink's System saw the light of day - see No such locomotives survive.

Convergent Axles coupled by means of Coupling Bars of Variable Length

Again of the five systems listed, only the Klose system was actually incorporated into locomotives - see and Such locomotives were used in the former Yugoslavia on the 760mm gauge, see pictures on this page (classes 189 and 191).

  Quill Transmission

I have used the phrase above which appears in Wiener's book but I prefer to use 'Hollow Axles'. It seems that Arthur Heywood was the first to describe and apply such a system - -but the chief patent belonged to two Germans after whom 'Klien-Lindner' axles are now known (and please note that the first of these two gentlemen is not 'Klein' as frequently appears). The Orenstein and Koppel locomotives of the Matheran Hill Railway used this system and were 0-6-0T - see elsewhere on this site for pictures of them at work. However, the vast majority of locomotives that used this system were 0-8-0T.

Necessarily all such locomotives had outside frames - there are more diagrams in Wiener's book see Bibliography. The diagram below shows how the drive on the outer axles was transmitted by a pin attached to a large ball to the actual driving wheels, this is taken from the Du Croo and Brauns book - see Bibliography. Underneath that is a picture of an actual axle (broken, with contents exposed) in Java where a huge number of locomotives were so equipped and a number were still active in 2009.

In practice, the original patent covered the basic idea and indicated that the outer axles should be connected to pivots in the centre of the locomotive to (hopefully) ensure that the outer axles behaved themselves when curves were exited. In practice, leaving them to sort themselves out passively was soon found to be inadequate and modifications had to be made. In the case of Orenstein and Koppel locomotives this meant adding springs, this is taken from the OK book - see Bibliography.

and for Maffei (and later related Du Croo and Brauns locomotives) this meant coupling the outer axles with a central pivot so they acted on each other, this is taken from the Du Croo and Brauns book - see Bibliography.

Other manufacturers of such locomotives (eg Borsig, Hanomag, Henschel and Jung also found in Java) had their own modifications but it would need one of them to be jacked up to examine the details and apart from a Borsig diagram in Wiener's book I have yet to see details published. I have too many pictures of such locomotives to include on this page:

Small 60 HP Olean 7 in 2005 is a typical example:

On the mainline in Java, two (very similar) classes used this system, this was D1503 on a Tegal to Pekalongan train in 1976. These locomotives frequently worked as 0-6-2s with the rear rods off.

Locomotives with extra Lateral Movement of Certain Axles

These are not included in Wiener's work and may not strictly be considered a form of articulation. However, since they competed directly with the types listed above, it is worth including them here. BMAG (formerly Schwartzkopff) produced a series of 0-10-0T in which there was extra lateral movement possible in the outer axles. The drive was taken on the central axle which was flangeless and this meant that the first, second, fourth and fifth axles could follow a curve while the third stayed aligned with the cylinders. The second, fourth and fifth axles have extra side play of about an inch with extended crankpins and naturally there had to be extra flexibility in the way the rods were connected. The diagram below by Roger West was first published in the Industrial Railway Record in 1975.

A feature of this design is a 'dummy' 6th axle which was intended to ensure things got back to normal quickly on the straight, but was left out of later designs. Both inside and outside frame varieties survive in Java, the first picture shows Sragi 7 in 2002:

All inside frame locomotives of this type in the sugar mills are out of service, but the Cepu Forest Railway has three of them, used on occasional charter trains these days, this picture was taken during such an event in 2002. 

Compared to this system, locomotives with Gölsdorf axles have all axles flanged and the one taking the drive can move outwards on a curve. See which includes a diagram for such an 0-10-0. Lie Tjeng Chiao assures me that the Hartmann 0-8-0T at Sragi sugar mill in Java have such a system, they certainly do not have Klien-Lindner axles as I know from crawling under one a long time ago... This picture was taken in 2002.

Rob Dickinson