INTRODUCTION
Queensland was separated from New South Wales on 6 th June 1859 when  Queen Victoria signed Letters Patent. At that time the colony had a  European population of only 25,000 spread over an area 670,500 square  miles (1736587 sq km). The new government was faced with the daunting  task of providing the necessary services. Limited income together with a  heavy capital works programme caused it to struggle financially in the  early years. The parliamentarians were aware that railways had  revolutionised transport elsewhere in the world and realized that such a  system would encourage inland settlement and development. Mr  Macalister, Secretary for Lands and Works, introduced the first Railway  Bill into Parliament on 19 th May 1863 . That initial goal, coupled with  financial restraints, was to influence railway development in the state  for the next century.
The first railway in Queensland from Ipswich to what is now known as  Grandchester opened on 31 st July 1865 . Work commenced on a line from  Rockhampton while the railway from Grandchester gradually extended  westwards. Another undertaking was commenced from Townsville in 1880.  Lines were progressively extended inland from the ports as part of the  government’s policy. Eventually, eleven isolated state government  railways were established and these together with four local government  shire tramways and the privately owned Chillagoe Railway became the  Queensland Government Railways. All with the exception of the Normanton  and (now closed) Cooktown railways were eventually linked together. The  process was slow and the North Coast Line was not completed until 1924.  The system’s expansion came to a halt in the Great Depression. It would  be more than two decades before another new railway was constructed.
At the outbreak of World War 2 there was a network of 6,500 miles  (10,400km), second only in length to South Africa for 3’6 ” gauge  railways. Unfortunately, much of it was built cheaply and consequently  was of light construction with sharp curves, steep grades and minimal  ballast. Only 1% consisted of 80lb (40kg) rail and half the system was  laid with lighter than 60lb (30kg) rails. Numerous timber trestle  bridges also existed and these imposed severe axle load restrictions  which was a restraint on locomotive sizes. Nevertheless, the railway  generally satisfactorily served its purpose at the time. Distant  communities and rural industries wanted frequent services and  politicians were determined that ‘their’ railway would provide them.  After all, the politicians’ future existence relied on keeping their  voters happy. This political interference caused many trains to run at  frequencies and to places that were not economically justified.  Ironically, some of those same politicians that demanded frequent and,  at times, subsidised services for their constituents were also the ones  who could be heard on other occasions bemoan the financial drain that  the railway was on Treasury. The lightly laid track was adequate in most  cases to handle the available loading. Other than during the hectic  years of World War 2, only on a few busy lines such as sections of North  Coast Line and Main Line to Toowoomba was there evidence of  deficiencies and required trains to be regularly double-headed and  banked over range sections. Not surprisingly these places were where the  early diesels did most of their work.
The railway was in a run down state after World War 2 due to deferred  maintenance and many locomotives and items of rollingstock, that would  have otherwise been retired, had been kept in service to handle the huge  demands. A massive rehabilitation programme was instituted to overcome  these problems and orders were placed for new locomotives and rollingstock. In 1948, the Chief Mechanical Engineer recommended that  the purchase of diesels be investigated. Fiscal restraints of the late  1940s and early 1950s no doubt had some bearing on the small size of  initial purchases. Also, probably railway officials were reluctant to  place large orders until they established what types would be most  suitable for local requirements. History later proved that this ‘wait  and see’ philosophy was justified as the twelve (what later were called)  1170 Class DEL , obtained in 1957/58, did not live up to expectations.
Development of the export coal market started a huge upsurge in traffic  in the mid 1960s (one that has continued through to today) and was the  catalyst that launched the system into a massive modernization and  upgrading programme. Many uneconomic branch lines were closed and by 30  June 1970 there were 389 diesels but only 15 steam engines on the  register. Improvements have continued since then and today QR is a  modern competitive railway, a far cry from what it was 50 years ago.
LOCOMOTIVE  DEVELOPMENT
The early railway had a distinctly English flavour with its officials,  locomotives and rollingstock being imported from Britain . In 1870s the  Baldwin Locomotive Works in USA was advertising that they could provide  cheaper locomotives than British manufacturers. This was sufficient  incentive to break Empire ties and three engines were imported from  America in 1877. Several more were obtained over the next seven years  until increasing government pressure to support local or British  manufacturers resulted in no further acquisitions from America until the  AC16 Class in 1943. In fact, by the turn of the century locomotives  were only obtained from outside the state when local manufacturers were  unable to supply.
Although early locomotives were mainly the design of their  manufacturers, some local modifications and experiments were performed.  Most notable of these were extended smokeboxes, deep fireboxes and  rocking grates. These successful innovations introduced in 1880s were  perpetuated in future designs and in many instances were fitted to  earlier engines as they underwent overhaul. Locals recognised suitable  features of existing engines and many of these were incorporated into  future designs and so Queensland Railways steam locomotives developed  into a mix of both British and American practice. The first truly  successful local design was the PB15 Class of 1889. It contained a  number of features that were to eventually become characteristic of  Queensland engines. Probably the most prominent of these was the “Baldwin” style sandbox mounted on top of the boiler. This had first  appeared on A12 engines imported in 1882 and continued to be  incorporated in new locomotives until 1953 when the last C17 was  delivered.
Engineers kept abreast with developments elsewhere and these were tried  and if found suitable adopted. Tests were carried out with both vacuum  and air brakes as early as 1877. Initially vacuum was considered the  most suitable and adopted. However improvement to the Westinghouse air  system caused fresh trials to be conducted in 1889. These proved the air  brake to be superior and so it became standard although previous fitted  vacuum stock continued to operate for some time. The advantages of  Walschaerts valve gear were acknowledged and it was fitted to the 6D16  engines built from 1901 and all future classes, except for the  experimental B16½. This engine was equipped with Southern valve gear  but that proved to be wanting. Economies from superheating were  recognised prior to World War 1. In 1914, C18 N°693 was fitted with a  Schmidt type superheater and was the first superheated engine to run on  QR. Electric headlights were used on engines on some unfenced lines as  early as 1918. By the late 1920’s it became policy to fit electric  headlights to all new locomotives except the D17 class which was  restricted to running in the Brisbane suburban area. With few  exceptions, all steam locomotives remaining in service by 1951 had been  so fitted. By 1920s, Queensland enginemen had the benefit of a number of  standard features that were not available to their interstate  counterparts. These included labour saving devices such as rocking  grates, hopper type ashpans with bottom discharge and smokebox ash  ejectors. Roller bearings were introduced in 1930s. All steam  locomotives built in the 20 th Century, except the AC16 and Garratt  Classes, were designed locally. The BB18¼ did however incorporate some  alterations suggested by Vulcan Foundry.
Unfortunately, the biggest factor influencing locomotive development was  finance, or more correctly the lack of it. Government policy prescribed  that loan monies were required for all new work while maintenance costs  were charged against operating revenue. Thus the Railway Department was  reliant on parliament for funding. This firstly affected the building  of new lines. Politicians were keen to expand the railway at minimum  cost and consequently construction standards were often as cheap as  possible resulting in the use of light rails, little or no ballast,  minimum earthworks, sharp curves and numerous timber bridges. Timber was  abundant in most areas and before the days of heavy earthmoving  equipment is was quicker and cheaper to build a timber bridge than to  construct an embankment. Draughtsmen and engineers constantly had to  struggle to design more powerful locomotives yet remain within the  constraints imposed by the standards of the permanent way. One method of  increasing power was to use small coupled wheels but that tactic  reduced the locomotives’ maximum capable speed. Conversely, larger  coupled wheels enabled greater speed but resulted in a less powerful  locomotive. In the latter part of the 19 th Century, the administration,  like many overseas counterparts, were acquiring two types of  locomotives; more powerful ones with smaller coupled wheels for goods  work and others with larger coupled wheels for faster passenger work.  Increasing mail train loads soon grew beyond the capacity of the faster  passenger engines. Designers then looked towards creating a ‘mixed  traffic’ locomotive with sufficient power to haul useful loads yet with  coupled wheels sufficiently large to enable handling passenger trains at  reasonable speeds. These goals set the design criteria for most classes  produced in the 20th Century. The PB15 with its 48″ coupled wheels  amply fulfilled this role. It was capable of hauling reasonable loads  yet its coupled wheels enabled speeds of up to 50 miles per hour. The  popular B18¼ Class, introduced in 1926, produced maximum possible power  for its adhesive weight and with 51 ” coupled wheels proved more than  capable of exceeding permissible track speeds. Still, Queensland  locomotives were small by world standards, even when compared with other  3′ 6″ (1067mm) railways. At the end of the steam era in 1970, 12 tons  was the highest axle load permitted for steam locomotives on the main  line. By way of comparison, this was approximately only two thirds of  that allowed by South Africa on their main lines and roughly equivalent  to their branch line limit. Financial constraints also inhibited the  development of some new designs and even in the case of a few completed  designs prevented their production. The most notable example of the  latter case was the proposed CC17 Class which was abandoned in 1953,  although the successful introduction of diesels also had some bearing on  that decision. Funds were also occasionally not forthcoming when  additional motive power was required to cater for increasing traffic.  This resulted in the regrettable, but necessary, repair of older engines  that had reached the end of their economic life. Such repairs being  classed as maintenance costs were treated as operating expenses.
Despite these limitations, Queensland’s steam locomotives generally  acquitted themselves well when compared with those of other systems.
LOCOMOTIVE CLASSIFICATIONS
An alphabetical system of classification was adopted after 1868. The  system was designed to group together engines with similar power ratings  to satisfy the Traffic Branch. Apparently in time confusion developed  due to, amongst other things, isolated railways applying their own names  rather complying with the established method. In a few cases the  builder’s name was included as part of the class title. The passenger  engines (later A12 class) that were introduced in 1882 never received a  class under the system but were always referred to as “American  Passenger” . The system became unwieldy and was eventually replaced.
The current classification method was adopted in 1889. Letters are used  to identify the number of coupled wheels followed by numerals indicating  the cylinder diameter in inches.
A, Four coupled; B, Six coupled; C, Eight coupled; D, Tank Locomotives
In the case of tank engines, the letter D was originally preceded by a  figure denoting the number of coupled wheels eg. 6D17. Use of the number  prefix was abolished from circa 1937. Where there was more than one  type that fell within these guidelines an additional prefix letter was  added to distinguish the difference. When a later model of an existing  class was introduced the practice was to double the letter eg. BB18¼,  CC19, DD17. In other cases where differences existed a different  additional letter was added. In the case of the AC16 Class, the A  indicates American while with the PB15 Class, P indicates Passenger. The  unusual step was taken in 1924 when an ‘ improved ‘ version of the PB15  class was introduced by denoting it by the addition of the year to the  normal classification i.e. PB15 1924. In later years, at least, the year  was rarely shown on locomotives. Another exception to the normal rule  was when members of the original B15 Class were altered. These engines  were referred to as B15 Converted, which for marking purposes was  usually shown as B15 Con. Australian Standard and Beyer Garratt  Locomotives were not given a classification code. A major deficiency of  the system was that it did not distinguish locomotives within these  classes that had altered features such as roller bearings, larger  tenders or improved braking.
The classification code was painted on the left hand side of the front  headstock.
There were shortened versions of some of these classifications in common  usage: ‘ B18 ‘ for (B)B18¼, ‘ D’ for D17, ‘ DD ‘ for DD17, ‘PB’ for  PB15 and ‘ Garratt ‘ for both types. At times these abbreviated names  were used in official documents. Another term that received some use in  the 1960’ s was ‘ Standard Class Locomotive ‘ . This was occasionally  used in Train Notices etc. to identify a B18.
In addition to these titles, many were commonly referred to by  nicknames;
| ‘Bety’ (from telegraphic code word) | BB18¼ | 
| ‘Yank’ | AC16 | 
| ‘Limousine’ | C17 with sedan cab | 
| ‘Brown Bomber’ | Roller Bearing C17 painted brown | 
| ‘Walschaerts’ | 1924 PB15 | 
| ‘Black Tank’ | D17 | 
| ‘Blue Tank’ or ‘Blue Baby’ | DD17 | 
| ‘Deep Sea Liner’ or ‘Bull’ | C19 | 
UNIT LENGTHS
At times it was necessary to identify the length of a particular train.  It was essential on single lines to know if a crossing loop had the  capacity to accommodate a train clear of the main line. A system of ‘  unit lengths ‘ was established to enable easy calculation of train  lengths. The unit was based on the length of a standard F wagon, 17 ‘ 6 ”  (5.33 metres). Train lengths were then referred to as the equivalent of  ‘ xx ‘ F. Later the letter ‘ F’ was omitted and the term ‘units’  applied solely. The length classification was marked on vehicles (except  suburban carriages and rail motor stock) and locomotives to enable  train lengths to be easily computed.
The unit length was altered to 5 metres after introduction of Metric  measurements
All steam locomotives still in service after 1 st February 1966 received  the marking on the front buffer beam adjacent to the class designation.  The length classification number was stencilled in 1¾” figures  enclosed in a 4 ” diameter ring.
| Class | Length Classification | 
| D17 | 2.2 | 
| DD17 | 2.3 | 
| PB15 | 2.8 | 
| C16 and C17 | 3.1 | 
| B18¼ and AC16 | 3.4 | 
| BB18¼ | 3.5 | 
| Beyer Garratt | 5.2 | 
DEPOT AND  DIVISION MARKINGS
Commencing in the late 1920 ‘ s, locomotives were marked with their  depot and Division. Both were generally recorded on the rear of the  tender with the depot identification being also shown on the right hand  side of the front headstock. From the late 1940 ‘ s, these marking were  omitted from metropolitan (Mayne, Wooloongabba and Ipswich ) engines and  later by other SED depots. In the Central Division, the depot was not  normally shown on the tender. The Beyer Garratts, when attached to  Rockhampton, had that depot ‘ s markings on both front and rear  headstocks but no divisional markings.
South Eastern  Division
SED
| B | – | Brisbane (i.e. Mayne) | 
| G | – | Gympie | 
| I or Ip | – | Ipswich | 
| M | – | Maryborough | 
| NB | – | North Bundaberg | 
| SB | – | South Brisbane (i.e. Wooloongabba) | 
Central  Division
CD
| A | – | Alpha | 
| E | – | Emerald | 
| Mk | – | Mackay | 
| Mt | – | Mount Morgan (closed 1952) | 
| R | – | Rockhampton | 
Northern  Division
ND
| C | – | Cairns | 
| CT | – | Charters Towers | 
| Cy | – | Cloncurry | 
| H | – | Hughenden | 
| T | – | Townsville | 
South Western  Division
SWD
| R | – | Roma | 
| T | – | Toowoomba (Willowburn) | 
| W | – | Warwick | 
Administrative  Divisions of QGR
In 1878, it was decided to group the existing and proposed railways into  three divisions: – Southern, Central and Northern. The Southern  Division was later split into two parts. The following lists and  describes the arrangement that existed during the latter part of the  steam era.
South Eastern Division
Main line and Branches between Brisbane and Helidon
North Coast Line and Branches between Brisbane and Avondale
South Western Division
Main line between Helidon and Toowoomba
All lines south and west of Toowoomba.
The South Western Division was amalgamated with the South Eastern  Division to form the Southern Division in 1984.
Central Division
North Coast Line and Branches between Avondale and Bloomsbury
Mackay Railway
Central Railway and Branches between Rockhampton and Winton
Northern Division
North Coast Line from Bloomsbury to Cairns
Townsville to Mount Isa and Winton
Cairns Railway
Normanton Railway
LOCOMOTIVE  NUMBERS
The entire Locomotive Branch was placed under the control of a newly  created position of Locomotive Engineer in 1883. By the end of the  decade this title was changed to Chief Mechanical Engineer (CME) and  again later to Chief Mechanical Engineer and Workshops Superintendent  (CME&WS). In conjunction with several other rearrangements,  locomotives and rollingstock were consolidated into one rollingstock  register in 1889-90. This resulted in most items, except those operating  on the original Southern and Western Railway (from Ipswich ), being  renumbered.
After 1889, numbers were applied chronologically in blocks as orders for  construction were issued. The outcome was, when contracts for  construction of different classes were being placed simultaneously, that  groups of numbers for one class appeared between blocks of numbers  allocated to another. Additionally, if the delivery of engines under a  contract was delayed, it could result in engines entering service not in  numerical sequence. E.g. BB18¼ 1089 entered service in March 1958 but  Beyer Garratt 1090 had entered traffic in May 1951.
During the period from 1910 to 1935 there was also a practice to re  issue numbers from locomotives that had been written off the register.  Not all numbers were reused. The highest number to be ‘ recycled ‘ was  340. AC16 engines retained their US Army numbers with the suffix ‘ A ‘  added to distinguish them from existing locomotives that had otherwise  identical numbers. Australian Standard Garratts retained the numbers  allocated to them by the Commonwealth Land Transport Board.
Builders and  Number Plates
Builder ‘ s Plates were supplied by the manufacturer to their own  design. Most were oval shaped, but a few companies opted for different  styles. Possibly the most impressive were those on engines supplied by  Clyde Engineering Works, Granville NSW. Engines built by Dubs & Co,  Glasgow carried an elongated diamond shape plate. Walkers Ltd used oval  plates but reduced their size in later years. Those engines supplied by  Baldwin in both centuries had round ones. With the exception to the  Baldwin built engines, where they were attached to the smokebox, builder  ‘ s plates were normally affixed to the cab sides. Some B15 engines  constructed by Evans, Anderson, Phelan and Walkers Ltd had additional  plates fitted to the tenders. Early engines manufactured by Walkers also  had a large circular plate incorporating a star and the company’ s name  affixed to the centre of the smokebox door. The first five C16 engines  and the six 6D13½ Class engines built at Ipswich had a combined builder  ‘ s and number plate on the cab sides. The ASG engines built at VR ‘ s  Newport Workshops were not fitted with builder ‘ s plates. It has been  said that the VR CME refused to allow them to be fitted lest he be held  responsible for the engines (and their defects).
Number plates were rectangular in shape and generally attached to the  first ring of the boiler on tender engines and to the sides of the  bunker on tank engines. Those on the 6D13½Abt engines were attached to  the smokebox. The ASGs carried a CLTB number plate on cab sides. AC16  engines were not supplied with number plates. The engine number was  painted on the cab side in the usual position for the builder’ s plate.  Engines of that class that were based in the Central Division also had  the number painted on the boiler where a number plate would normally be  attached. The PB15 engine, N°12, purchased from Aramac Shire Council in  1958 was not fitted with a number plate but had the number painted on  the boiler where number plates would normally be affixed. Prior to 1929,  except on the 6D13½ Abt engines, number plates also carried ” N°” in  advance of the numerals. Number plates and most builders ‘ plates were  made of brass with their background painted red except for the roller  bearing C17s where it was green. Baldwin builder’ s plates attached to  smokeboxes were painted black.
Naming of  Locomotives
The first four engines imported into Queensland were given names but  thereafter engines were normally only issued with numbers. The next  engines to received names were C18s (later CC19s) N°693 and N°694  when, in 1915, they were named Sir William MacGregor and Lady MacGregor  after the then Governor of Queensland and his wife. In 1923, C19 N°702  was named as “Century ” as it was the 100 th engine constructed at  Ipswich Workshops. Several of the Ipswich Workshops shunt engines were  called ” Pompey” during their tenure. In recognition of this, a name  plate was fitted to the front of the last steam incumbent B13½ N°398.  When DD17 N°1051 was restored to working order it was named ” The Blue  Baby ” and fitted with a name plate. Since their introduction, various  DELs have been given names.
{mospagebreak title=Liveries}
LIVERIES
Some PB15 class engines were painted Quaker green prior to WW1. Three  early C16s were specially painted (N° 427 chocolate, N° 428 royal blue  and N° 429 green) for working the Sydney Mail Train. Smokeboxes were  black japanned. From then until the batch of B18¼ engines built in  1936-37, the clothing of boilers, cylinders etc. was planished mild  steel sheet of a light blue colour. Engine buffer beams were painted  signal red from 1935.
By 1940, all engines were painted black enamel with red buffer beams,  builder ‘ s and number plates. Brass boiler bands were not painted. Some  brass dome covers were also not painted or had previously applied paint  removed. The canvas cover on timber cab roofs was painted black until  1952, when red oxide was substituted. The steel cab roofs on BB18¼,  DD17 and Beyer Garratts were painted black.
The following liveries were introduced in 1949: –
| B18¼/BB18¼ | – | Hawthorne Green and carmine red trim | 
| C17 | – | Chocolate brown and willow green trim | 
| DD17 | – | Royal blue, later midway blue, and red trim | 
| Beyer Garratt | – | Midland red and chrome yellow trim. | 
BB18¼ class entered service in the new colours and B18¼ engines were  gradually repainted green, commencing with N°50 and N° 911 in 1949.  DD17 N°949 entered service painted black in 1948. The next engine,  N°950, was painted royal blue for exhibition at Queensland Industries  Fair in 1949. The remainder of the batch, N°951 & N°954, were also  painted royal blue when they entered service in 1949. N°949 was  subsequently repainted to conform to the new colour scheme. The next  batch, N°1046 & N°1051, entered service painted midway blue. The  first six engines were later repainted in this colour.
It was intended that only the roller bearing C17s (N°961 & N°1000)  were to be painted brown. However, several older engines also received  this treatment. Instructions were subsequently issued that this colour  scheme was to be restricted to roller bearing engines. Those earlier  engines that had been repainted brown then reverted to standard black.
Some non standard features appeared at different times (B18¼ N°50 had  blue trim in its final days) Central Division engines had the steam end  of WH pumps painted red & green in case of roller bearing C17s.
Tyre walls were painted white at various times.
In conjunction with the phasing out of steam, engines receiving workshop  attention from 1967 were painted in standard black enamel with red  trim. This resulted in several B18¼, BB18¼ and roller bearing C17  engines returning to service in black livery. No DD17 or Beyer Garratt  engines were affected by this policy.
CLASS  DESCRIPTIONS
Separate descriptions are provided for all classes of steam locomotives  that operated on QGR during the 20 th Century. These contain notes on  each class together with their principal dimensions and lists of the  numbers built, when they entered service and were finally written off.  Wheel arrangements are identified using the Whyte method. This system  was designed by Frederic Whyte and became standard in UK , USA and  Australia whilst some European railways adopted another method. Under  the Whyte system 4-6-0 = ooOOO etc. Some wheel arrangements were also  given names eg Mikado for 2-8-2 and Pacific for 4-6-2 . Tank engines are  identified by the letter ‘ T ‘ appearing after the arrangement. The  majority of the information is self explanatory but the following are  brief descriptions of Adhesive Weight, Axle Loads, Superheating,  Tractive Effort and Written Off.
Adhesive  Weight and Factor of Adhesion
For a steam locomotive to have good  adhesion, it is important to have sufficient weight on the coupled  wheels. The weight bearing on the coupled wheels is called Adhesive  Weight. This weight divided by the tractive effort is called the factor  of adhesion. It has been found that a factor of adhesion of around 4 is a  good balance of pulling force and engine weight.
A locomotive will be “slippery ” if the factor of adhesion is low (less  than four). Because of the general weight and axle load restrictions  imposed on QR engines, the B18¼, BB18¼ and C17 classes particularly  suffered from low adhesion. This resulted in their full theoretical  tractive effort not being available. Consequently their scheduled loads  were less than had that been the case.
Axle Loads
Axle loads indicate the maximum weight present on any axle. These  amounts are expressed in tons. That load and the overall weight dictated  on which lines the locomotives could operate. Basically, lines were  divided into three categories.
Main lines were laid with 60lb or heavier rails and capable of  supporting a 12 Ton Axle Load (TAL) and the heaviest steam locomotives.
The next strongest lines were generally known as C16 standard lines.  Some of these contained 60lb rails but many were laid with 41¼ or 42lb  rails. At first they had a limit of 8 tons but over the years this was  progressively increased to 8.25, then 8.9 and finally 9.25 TAL. They  were available for C16, C17 and AC16 (fitted with a C16  tender) engines.
Light branch lines were originally only available for B13 Class engines  could carry a 7 TAL but this was later increased to 8 tons and they were  usually referred to as B15 standard lines. They were all laid with 41¼  or 42lb rails. They were available for B15 and PB15 engines.
The Etheridge and Normanton Railways were of a lighter standard although  the former was upgraded after the demise of steam.
The reciprocating motion of a steam locomotive causes a ” hammer blow”  effect on the track and bridges. This is not present with Diesel  Electric Locomotives and thus heavier axle loads are allowed with that  type of motive power. E.g. lines available to 12TAL steam were suitable  for 15TAL DEL.
In some instances, bridges imposed more severe restrictions than the  remaining track structure and were the limiting factor particularly in  relation to running of attached engines.
Superheating
Superheated steam has less water vapour and will therefore not condense  as rapidly as ‘wet’ or saturated steam. Its use leads to substantial  savings in coal and water comsumption. Superheated steam is produced by  passing steam through a superheater after its production in the boiler.  The equipment consists of a header, containing two portions, mounted in  the smokebox next to the tube plate. One portion collects saturated  steam from the internal steam pipe and from there passes the steam  through a series of elements situated inside the larger flue tubes of  the boiler. The steam ‘ s temperature is raised during this passage and  it is collected in the other portion of the header. From there it passes  through pipes to the steam chests. The process does not affect the  pressure of the steam but raises its temperature by 130°C, or more in  favourable circumstances.
Tractive  Effort
Tractive effort is a theoretical quantity. Railways preferred to use it  for steam locomotives rather than horsepower ratings because horsepower  involved a time quantity which was determined, in part, by how well the  locomotive was being fired (among many other variables). Tractive  effort, on the other hand, was decided strictly by the geometry of the  locomotive. Tractive effort is calculated by the standard Phillipson  formula:
| Tractive Effort | = | d² X S X BP* | 
|  |  | D | 
| Where: – | d | = Diameter of Cylinder (inches) | 
|  | S | = Stroke of Piston (inches) | 
|  | BP | = Boiler Pressure (psi) | 
|  | D | = Diameter of Driving Wheels (inches) | 
*For superheated engines 85% of BP is used in calculations
*For saturated engines 80% of BP is used in calculations
*For some 19 th century engines only 70% of BP was used in calculations
The truly available tractive effort will not generally exceed one  quarter of the adhesive weight.
Written Off
All locomotives and rollingstock were recorded as assets in a register.  The term ” Written Off ” or ” Written off the Books ” was used to  describe them being removed from that record. This inventory was  maintained for accounting purposes and there were occasions where  engines had been out of service for considerable time before they were  removed from the register. This particularly applied to some engines  that were set aside during the Great Depression but were not taken off  the books until several years later. Conversely, at the end of the steam  era there were incidents of engines being written off while they were  still in use. One B15Con was removed in 1942 but repaired and returned  to the register in 1943 to be finally written off in 1957. A similar  situation occurred with a few C19s in 1950s.
QUEENSLAND  RAILWAYS
For most of the 20th Century, the government owned railway in Queensland  was known as Queensland Railways (QR), Queensland Government Railways  (QGR) or at times simply as the Railway Department. These names were  used interchangeably over the years and a similar approach has been used  in these texts. The latter title was mainly reserved for internal and  government matters.
UNITS OF  MEASUREMENT
Since steam locomotives were built and operated when the Imperial system  of measurements was used in Australia , these units have been used  throughout the tables. For those desiring to convert these figures to  Metric units the following table maybe useful: –
| 1 inch (1″) | = | 25.4mm | 
| 1 foot (1′ ) | = | 305mm | 
| 1 chain | = | 20.117 metres | 
| 1 mile | = | 1.609 km | 
| 1 square foot (sq ft) | = | 0.0929 sq metres | 
| 1 gallon | = | 4.546 litres | 
| 1 pound (lb) | = | 0.454 kg | 
| 1 ton | = | 1.016t | 
| 1 lb per square inch (psi) | = | 6.895 kilopascal | 
When Decimal Currency was introduced on 14 th February 1966 one pound  (£1) converted to $2. Twelve pence (d) equalled one shilling (s) and 20  shillings (s) equalled £1. However, inflation and other issues make  conversion of monetary amounts meaningless unless these factors are  known and taken into consideration. An amount of one pound, two  shillings and six pence was expressed thus: – £1/2/6.