Articulated Engines 101: The Meyers

Añadido: 2026-05-11

[00:00:00]As the steam age pressed on, demand for more powerful locomotives grew.

[00:00:05]Naturally, the way to make a steam engine more powerful is to make it bigger. But there's only so big you can make a locomotive before it's unable to negotiate turns without destroying the rails. This required engineers to find ways of making locomotives more flexible. And in this video, we're going to take a look at one of the ways they did it.

[00:00:29]Today we're looking at mayor engines.

[00:00:32]The general design of the mayors is pretty straightforward. Where on a traditional steam locomotive the driving wheels are rigidly connected to the frames carrying the boiler, on a mayor the driving wheels are part of a separate bogey which is connected to the frame carrying the boiler by a rotating joint. These bogeies contain the driving wheels as well as the cylinders and valve gear needed to drive them with steam being transferred from the boiler to the cylinders via a flexible pipe.

[00:01:00]Each mayor has two of these bogeies, one mounted towards the front of the engine and one towards the rear. Typically, the cylinders would be set inwards closer to each other near the center of the locomotive, but their positioning often varied between designs. some facing forwards, some backwards, some inwards, and some outwards. Because these bogeies were connected to the frame by rotating joints, it allowed them to swivel when going around bends, providing greater flexibility compared to similarsized traditional engines with wheels fixed to their frames. Another bonus was having two sets of driving wheels generally meant the Mayers had more pulling power than a conventional locomotive. The fuel and water being carried on the same frame as the boiler also helped provide more adhesive weight, improving traction. The first example of a Mayor locomotive appeared in 1851. Designed by Austrian engineer Wenzel Gunther for the Searing Trials, known as the Vina Noat locomotive, it performed well at the trials, but the flexible steam pipes proved to be problematic and overall couldn't articulate as much as desired.

[00:02:08]It wouldn't be until 10 years later in 1861 that French engineer Jeanjac Mayor would patent the design, giving it its name. And in 1868, he produced an 0440 named Levvenir. With the cylinders positioned close to one another, it allowed for some variations to be compounded, making them much more efficient steamers. The design took off and became quite popular in Europe, primarily on lines with strict loading gauges or on narrow gauge rails, as these typically had tighter bends. As flexible steam pipes improved, so too did the Mayor designs. But there were, however, a few issues with them. The first being their speed. Most mayors had comparatively small driving wheels and often lacked guiding or trailing wheels.

[00:02:54]This meant they rarely traveled at high speeds and often rode rough when they did, making them undeal for passenger or express work. On top of that was their fireboxes. Conventional locomotives usually had space beneath their frames to allow for deeper fireboxes, which helped improve steaming characteristics.

[00:03:14]Because the wheels of the mayors needed space to articulate, however, there was no room for a bigger firebox underneath.

[00:03:21]This proved to be a severely limiting factor of the design until a solution was found in 1894 when kiten and company of leadeds England received an order from the Anglo-Chile nitrate and railway company for several mayor engines.

[00:03:36]Locomotive superintendent of the railway, Robert Sterling, essentially suggested making the engines slightly longer at the back so as to leave a gap under the frames which provided space for a bigger firebox. This resulted in a Mayor engine with a much better firebox with the added bonus of having a bigger cab as well as more space for coal and water storage. Though bigger, the engines remained quite flexible and their improved fireboxes managed to put them on par with the Garretts in terms of power. This made them a good alternative to Garretts on railways in Africa and South America where the loading gauge couldn't support them.

[00:04:13]some even working on rack railways in Chile and Argentina. Because of the altered wheel arrangement, an extra chimney had to be fitted to the rear end of many kits and mayors to allow for the rear cylinders to exhaust properly. This however was one of the many drawbacks of the design as it meant the exhaust steam wasn't being used to draw air through the boiler like it was with the forward cylinders, significantly worsening steaming characteristics. On top of that, they were quite maintenanceheavy compared to many of the alternative articulated designs. As a result, despite being a general improvement on the standard mayor design, the Kitson mayors weren't as popular as the originals with around 100 being built.

[00:04:56]One last evolution of the Mayor design came about in 1936, built by WG Bagnel of Stafford. This was more in line with the standard Mayor design, but with a few alterations, including a bullhead boiler with a round firebox. A few of these were built for use on sugarcane railways in Africa, but were found to be less than satisfactory performers, being generally underpowered, difficult to maintain, and poor steamers. One reportedly taking up to 16 hours to get up to full steam. The only Bagnel engine to receive any praise was used domestically and even then it often suffered from its steam and exhaust pipes cracking. Despite its drawbacks, the standard Maya design seemed to be the most popular and reliable of the three variations with hundreds of engines being built for use in central Europe. Some of the most well-known examples are the Dubu scale locomotives and the Saxon 4Ks, the latter still working as late as 1994.

[00:05:56]Their power, flexibility, and compact size made them ideal machines for many steep, winding, narrow gauge railways.

[00:06:04]While not as powerful as the Garretts or males, their flexibility more than made up for it. So, if you're running a mountain railway and need something flexible, a mayor may just be what you need.

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