It just occurred to me that the NSWGR numbering system helpfully provides a guide to how rail was developing in this period, which may be useful for tweaking scenario scripting. What they did was name each class after the road number of the first in the class, with locomotives on the separate northern (Newcastle) network being numbered separately from the southern (Sydney) units. The northern ones ones were given an "N" suffix, so the 1 Class was a Sydney class and the 1N Class was a Newcastle class.
The Sydney network started with the 1 Class, which was four mixed traffic 0-4-2's in 1855. They got a fifth in 1856, which had detail differences so was designated the 5 Class. They also got two dedicated express locos in the same year: the 6 Class 2-2-2 (road numbers 6 and 7). This tells me that while starting with mixed traffic locos was obviously sensible, within a year they had already decided that they needed dedicated express haulers more than they needed dedicated freight haulers. So the scenario should develop express traffic fairly rapidly in the early years, which is an easy thing to arrange by event (temporary pax production increase).
The Newcastle network opened in 1857. The 1N Class was the same as the Sydney 1 Class, and it started with four locomotives in that class (road numbers 1N to 4N). So if playing for realism you wouldn't build anything at Newcastle for the first two game years. It may be worth scripting a separate territory to enforce this, as early haulage down the flat Hunter Valley terrain is often a good start in RT3. On the other hand having an 1857 northern opening enforced by scripting will reduce replay value, so may not be a good thing.
In 1858 the Sydney network got the 8 Class, which was a single 2-2-2 well tank unit. Obviously short haul express traffic was becoming even more important around Sydney. By this stage Sydney had five mixed traffic locos and three express locos, while Newcastle had four mixed traffic locos. The Sydney line reached Campbelltown in this year, while the Newcastle line still didn't go past Maitland.
The NSWGR stuck with the above locomotives (12 units in total, for both networks) until 1861. In that year five more locomotives were introduced, and they were all dedicated express units. The 9 Class 2-2-2 (
this beastie) was the same unit as the 5N Class, with three going to Sydney and one going to Newcastle. Sydney also got the 12 Class 2-2-2 well tank, which was a slight variant of the 8 Class. This brings Sydney up to five locos for mixed traffic and seven locos for express (five for longer hauls, and two suburban tanks) so clearly express was the majority of traffic in the Sydney area by 1861, while in Newcastle it wasn't as important but was becoming a factor.
After this nothing changes until 1863, when the Newcastle network received the 6N Class 4-4-0T (road numbers 6N and 7N). These were the first dedicated freight units on the NSWGR, for short haul mining traffic. At the time there were coal mines around Newcastle itself, and it wasn't necessary to go far up the river to get coal (the line only reached Singleton in this year anyway) but Newcastle had been exporting coal since the late 1700's and it was a major part of the economy by the mid 19th century. It's unusual that these units were 4-4-0T's, bearing in mind that these were a UK design for low speed short haul freight and 4-4-0's weren't a UK thing at the time. It may say something about the quality of the track around the collieries, since the 4-4-0 was introduced in the US largely because it could follow poorly laid track. Sydney got the 13 Class 2-4-0 in the same year, indicating they had enough express capacity for the moment and wanted more mixed traffic capability. This was also the year when the Sydney line reached Penrith.
The only deliveries in 1864 all went to Newcastle. There was one express unit: the 8N Class, which was a sort of mutant 5N. There were also two 0-6-0 saddle tank grunters: the 9N Class. As 0-6-0ST's they would have been colliery/dockside units, so short haul freight is still the predominant haulage in the Newcastle area.
In 1865 the Sydney crew started getting serious about crossing the Blue Mountains. The line from Penrith to Glenbrook didn't actually open until 1867, but they were clearly planning ahead and knew they would need some real hauling ability. The southern line extension to Picton and Goulburn was also being planned at this stage, and that meant long hauls and grades too. So, in 1865 Sydney received another seventeen locomotives, more than doubling its existing roster in one hit.
Two of these were the 14 Class 2-2-2, an express choof noted for hitting 70 mph occasionally (even though they weren't really supposed to). These were used on the flatter area around Sydney itself, particularly the Penrith run. The next nine units were the 17 Class 0-6-0, the first dedicated freight grunters on the Sydney network. Six went to Sydney, and three went to Newcastle as the 11N Class (more of these were delivered to both networks in later years).
Sydney also received nine 2-4-0's: the 23 Class. It seems the single unit in the 1863 13 Class had been a trial run for a future order of 2-4-0's. Apparently the 23 Class were mainly used for passenger traffic on lines which didn't suit the 2-2-2's. They turned out to be a bit short of grunt over the Blue Mountains line, once it opened, so another four of the class were ordered with slightly smaller driving wheels in 1869 (the year in which Lithgow and Goulburn were connected).
After this things developed fairly normally until the mid 1870's, with both Sydney and Newcastle receiving a mix of locos that was slanted towards freight. For RT3 purposes the locos involved weren't significant.
The next big change came in 1877. By 1877 the Newcastle line was heading for Tamworth, Orange had been connected, and the southern line was down to Cootamundra. It had also been decided that the NSWGR was going all the way out to Bourke, to steal the lucrative Darling River trade that was going to Victoria and South Australia (at the time the colonies didn't think of themselves as one country, and were very competitive little mongrels). All of this meant more locos and better ones were needed, so they went and got them.
26 of the Class 79 4-4-0's arrived on the docks in Sydney, with four of them going to Newcastle as 27N-30N. They liked them so much that another 38 units were delivered over the next few years: 30 to Sydney and 8 to Newcastle. From looking at the plans for the 79 Class and the 23 Class it's clear the 79 Class is basically the smaller driving wheels version of the 23 Class, but with the two wheel front truck changed for a four wheel truck. My guess is a lot of the parts came from the exact same castings. The 79 class became the leading NSWGR express locos over the next decade.
In 1877 the NSWGR also decided to trial 2 Baldwin 4-4-0's (NSWGR 105 Class, Baldwin designation 8-30). They must have thought it was ok because a third one arrived in 1879, but no more were ordered. It may simply have been that by now they had enough express capability on the tracks and already ordered, so didn't see the need for more Baldwins. 1877 also saw the introduction of the 93 Class 0-6-0's. They got 50 of those, which turned out to be so good that they got another 30 later. Half of them were still in service 50 years later, and two kept running until 1972.
For a 25 year scenario starting in 1855 the last year of play is 1879, when the NSWGR finally got around to trying out Connies.
They got 11 Connies from Baldwin, which were the standard 10-34 production model of the time. Connies would be a nice last year addition to the scenario (although everyone would probably be grumbling about not getting them earlier).
If anyone wants to know, for the 1880's they apparently went nuts on Moguls. No idea why, but they got stacks of the things in four different classes: 70 units from Beyer Peacock and 30 from Baldwin. They also got another 60 4-4-0's (not the 79 Class) and a couple of other odds and ends.
just because it works so well. The only catch was because it was an experiment I tried it on a sandbox rather than the game map itself, which means I have to do it all over again on the game map. 
