We Are Number One Tank Engine

We Are Number One Tank Engine

prepare your ears Y O U H A V E B E E N W A R N E D thomas the tank engine and trumpet music. [Redhead Kid] “So this is what my life has become. Pointlessly watching trains while waiting for somebody to push me off this bridge to solve the trolley problem” In case you were wondering, here is an except of the definition of Tank Locomotive from Wikipedia “Tank engine” redirects here. For the fictional work, see Thomas the Tank Engine. For the engine of an army tank, see tank (vehicle).

LB&SCR J1 class
A tank locomotive or tank engine is a steam locomotive that carries its water in one or more on-board water tanks, instead of a more traditional tender. A tank engine may also have a bunker (or oil tank) to hold fuel. There are several different types of tank locomotive, distinguished by the position and style of the water tanks and fuel bunkers. The most common type has tanks mounted either side of the boiler. This type originated about 1840 and quickly became popular for industrial tasks, and later for shunting and shorter distance main line duties. Tank locomotives have advantages and disadvantages compared to traditional tender locomotives. Origins[edit]

A modern replica of Novelty, the first tank locomotive
The first tank locomotive was the Novelty that ran at the Rainhill Trials in 1829. It was an example of a Well Tank. However, the more common form of Side tank date from the 1840s; one of the first of these was supplied by George England and Co. of New Cross to the contractors building the Newhaven, Sussex branch line for the London Brighton and South Coast Railway in 1848.[1] In spite of the early belief that such locomotives were inherently unsafe,[2] the idea quickly caught on, particularly for industrial use and five manufacturers exhibited designs at The Great Exhibition in 1851. These were E. B. Wilson and Company, William Fairbairn & Sons, George England, Kitson Thompson and Hewitson and William Bridges Adams.[3] By the mid-1850s tank locomotives were to be found performing a variety of main line and industrial roles, particularly those involving shorter journeys or frequent changes in direction.

Types of tank locomotive[edit]
There are a number of types of tank locomotive, based on the location and style of the water tanks. These include the side tank, the saddle tank, the pannier tank, the well tank and others.

Side tank[edit]

A typical side tank locomotive from 1897

An example with a tapered front and an access aperture
A configuration very common in the U.K. The water is contained in rectangular tanks mounted on either side of the locomotive, near to the boiler but not quite touching. The tank sides extend down to the running platform, if such is present, for at least part of their length.

The length of side tanks was often limited in order to give access to the inside motion. If it was desired to extend them to the front of the locomotive for greater capacity, access could be facilitated by apertures provided at the appropriate location. With larger side tanks it was sometimes necessary to taper the tanks slightly at the front end to improve forward visibility. Side tanks almost all stopped at, or before, the end of the boiler barrel, with the smokebox protruding ahead. A few designs did reach to the front of the smokebox and these were termed ‘flatirons’.

Saddle tank[edit]

A typical curved saddle tank

A saddle tank with both straight sides and a protruding smokebox
The water tank sits on top of the boiler like a saddle sits atop a horse. Usually the tank is curved in cross-section, although in some cases there were straight sides surmounted by a curve (like an inverted ‘U’), or even an ogee shape (a concave arc flowing into a convex arc). Saddle tanks were a popular arrangement especially for smaller locomotives in industrial use. It gave a greater water supply, but limited the size of the boiler and restricted access to it for cleaning. However, the locomotive has a higher centre of gravity and hence must operate at lower speeds. The driver’s vision may also be restricted, again restricting the safe speed.

Water in the tank is slightly pre-heated by the boiler, which reduces the loss of pressure found when cold feedwater is injected into the boiler. However, if the water becomes too hot, injectors lose efficiency and can fail. For this reason, the tanks often stopped short of the hotter and uninsulated smokebox.

Large USA 2-8-2T saddle tank. Note the short tank, avoiding both firebox and smokebox
The squared-off shape of the Belpaire firebox does not fit easily beneath a saddle tank, and so most saddle tanks retained the older round-topped boiler instead. A few American locomotives used saddle tanks that only covered the boiler barrel, forward of the firebox.

Wikimedia Commons has media related to Saddle tank locomotives.
Pannier tank[edit]

Pannier tank: GWR 57xx class
Pannier tanks, in Britain used almost exclusively by the Great Western Railway, and also common in Belgium, are box-shaped tanks carried on the sides of the boiler like a pannier is carried by pack animal. Unlike the side tank, they do not go all the way down and there is space between the tank and the running plate. The pannier arrangement lowers the centre of gravity compared to a saddle tank, whilst still allowing easy access to the inside motion that the latter gave. The first Great Western pannier tanks were actually converted from saddle tank locomotives[4] when these were being rebuilt in the early 1900s with the Belpaire firebox. There were difficulties in accommodating the flat top of the latter within an encircling saddle tank which cut down capacity and increased the tendency to overheat the water in the tank.[5] In Belgium, pannier tanks were in use at least since 1866, once again in conjunction with Belpaire firebox locomotives built for the Belgian State and for la Société Générale d’Exploitatation (SGE), a private company grouping smaller secondary lines.[6] Pannier tank locomotives are often seen as iconic of the GWR.

Wikimedia Commons has media related to Pannier tank locomotives.
Well tank[edit]

A well tank

A well tank formerly used on London suburban services
In this design, used in earlier and smaller locomotives, the water is stored in a ‘well’ on the underside of the locomotive, generally between the locomotive’s frames. This does not restrict access to the boiler, but space is limited there, and the design is therefore not suitable for locomotives that need a good usable range before refilling. The arrangement does, however, have the advantage of creating a low centre of gravity, creating greater stability on poorly laid or narrow gauge tracks. The original tank locomotive, Novelty, was a well tank.

Rear tank (or back tank)[edit]

A rear tank
In this design, the tank is placed behind the cab, usually over a supporting bogie. This removes the weight of the water from the driving wheels, giving the locomotive a constant tractive weight. The disadvantage is a reduction in water carrying capacity. A rear tank is an essential component of the American Forney type of loco, which is essentially a 4-4-0 American-type with wheels reversed.

Wing tank[edit]
Wing tanks are side tanks that run the length of the smokebox, instead of the full length of the boiler. They were mainly used on narrow gauge industrial locomotives that could be frequently re-filled with water and where side or saddle tanks would restrict access to inside valve gear. See Kerry Tramway Excelsior which has been described, by various sources, as both a wing tank and an inverted saddle tank.

Inverted saddle tank[edit]
The inverted saddle tank was a variation of the Wing Tank where the two tanks were joined underneath the smokebox and supported it. This rare design was used for the same reasons as the wing tank but provided slightly greater water capacity. The Brill Tramway locomotive Wotton is believed to have had an inverted saddle tank. The inverted saddle tank seems to have been a speciality of W.G.Bagnall.


The LSWR 415 class combined side tanks and a well tank
Large side tank engines might also have an additional rear tank (under the coal bunker), or a well tank (between the frames). This may have been to increase the water capacity, to equalise the weight distribution, or else improve the stability by lowering the centre of gravity.

A tank locomotive may also haul a tender behind it. This is usually found on narrow gauge railways where the small size of the locomotive restricts the space available for fuel and water. Where a tender was used it usually carried only fuel with the locomotive’s water tanks remaining in place. The tender offered greater fuel capacity than a bunker on the locomotive and often the water capacity could be increased by converting redundant bunker space into a water tank.

Wheel arrangement[edit]
While a tender engine might be described as an 0-6-0, the matching tank engine would be described as an 0-6-0T for a plain tank, an 0-6-0ST for a saddle tank, and so on (‘PT’ indicating a pannier tank, ‘WT’ a well tank, and ‘CT’ a crane tank, etc.)

Because tank locomotives are capable of running equally fast in both directions (see below) they usually have symmetrical wheel arrangements to ensure the same ride and stability characteristics regardless of the direction travelled, producing arrangements with only driving wheels (0-4-0T and 0-6-0T) or equal numbers of leading and trailing wheels (2-4-2T, 4-6-4T etc.). However other requirements, such as the need to support a large bunker, would require a non-symmetrical layout such as 2-6-4T.

Exceptionally, when many of the surplus New South Wales 30 class locomotive were converted from tank engines to tender engines, the tender engines were described as 30T class.

Fuel bunker[edit]

A rear bunker.

A side bunker.
On a tank locomotive the fuel (most often coal) is carried in a bunker the location of which can vary. On a locomotive with a trailing carrying axle or a trailing bogie the bunker is generally situated to the rear of the cab, but in cases where the firebox overhangs the rear driving axle, it has been common practice to situate the bunker on top of and to one side of the firebox; this concentrates the weight and stabilises the locomotive.

Other types of tank locomotive[edit]
There are several other specialised types of steam locomotive which carry their own fuel but which are usually categorised for different reasons.

Garratt locomotive[edit]

South African Railways NGG16 class Garratt, preserved in Wales.
Main article: Garratt
A Garratt type of locomotive is articulated in three parts. The boiler is mounted on the centre frame without wheels, and two sets of driving wheels (4 cylinders total) carrying fuel bunkers and water tanks are mounted on separate frames, one on each end of the boiler. Articulation is used so larger locomotives can go around curves which would otherwise restrict the size of rigid framed locomotives. One of the major advantages of the Garratt form of articulation is the maintenance of the locomotive’s centre-of-gravity over or inside the track centre-line when rounding curves. Some other forms of articulation, notably the Mallet, tend to move the centre-of-gravity outside the centre-line on tight curves, leading to problems with traction and stability.

Crane tank[edit]

A crane tank preserved as a static exhibit at Bressingham.
Main article: Crane tank
A Crane tank (CT) is a steam tank locomotive fitted with a crane for working in railway workshops or other industrial environments. The crane may be fitted at the front, centre or rear.

Streamlined tank locomotives[edit]
During the 1930s, there was a fashion for express passenger locomotives to be streamlined by enclosed bodyshells. As express locomotives, these were nearly all tender locomotives. A few examples of fast tank engines were streamlined though. These were used on high-speed, but shorter, services where turn-around time was important and the tank engine’s independence from turntables was useful. Examples included the German Class 61 and the Hungarian Class 242.

Contractor’s locomotive[edit]
The contractor’s locomotive was a small tank locomotive specially adapted for use by civil engineering contractor firms engaged in the building of railways. The locomotives would be used for hauling men, equipment and building materials over temporary railway networks built at the worksite that were frequently re-laid or taken up and moved elsewhere as building work progressed. Contractor’s locomotives were usually saddle or well tank types (see above) but required several adaptations to make them suitable for their task. They were built to be as light as possible so they could run over the lightly built temporary rails and had deeply flanged wheels so they did not de-rail on the tracks which were often very uneven. At the same time they had to be very powerful with good traction as they would often have to haul trains of wagons up very steep gradients, such as the sides of railway embankments or spoil heaps. Many were designed so that large iron ballast blocks could be fitted to the frames when extra weight and traction was required, then removed when it was not. Most had sanding gear fitted to all wheels for maximum traction. Some method of keeping mud and dust from clogging the wheels and brake shoes was also required – this either took the form of scraper bars fitted to the leading edge of the wheels or wheel washer jets supplied from the water tank. To handle long trains of loose-coupled (and often un-sprung) wagons, contractor’s locomotives usually had very effective steam-powered brakes. Most lacked a full cab, often only having a front ‘spectacle plate’. If a cab was provided it was usually removable along with the chimney, and sometimes the dome, so that the locomotive could be loaded onto a flatbed wagon for transport to new locations by rail whilst remaining within the loading gauge.[citation needed] because the more you know The end You can leave now thats it its over theres nothing more to see just click there there there or there or dont subscribe to the channel if you want to not that you have to why are you still here do you have some kind of dare you have to fulfill some kind of “finding yourself?” because you won’t “Find Yourself” Here so you should leave or give up or stay or do both or maybe even do each of the aforementioned options all at the same time or at different times or not at different times theres literally no reason to continue reading this alright were finished here goodbye as in you can leave now GOODBYE G O O D B Y E

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