Christian Woolley has wrote a little bit about the history of the
IOMR for those of you that are not au fait with it:

Basically the Isle of Man Railway system comprised of 4 lines, The
Douglas - Port Erin line, Douglas to St Johns, the St Johns to Ramsey
and St Johns - Peel. At various other times smaller branch lines came
from these, most notabley the Foxdale branch line which ran south
from St Johns.

The first line from Douglas-Peel (11 miles) was opened in 1873, and
three beyer peacock tank engines (2-4-0's) were ordered. These were
No.1 Sutherland, No.2 Derby and No.3 Pender. Named after various
supporters and dignitaries. Stations were provided at Douglas, Kirk
Bradden, Union Mills, Crosby, and St Johns. The year after in 1874, a
further line to Port Erin in the South of the Island was opened,
built by 400 navvies. Some 15 miles long, the line had steeper
gradients. Stations were provided at Port Soderick, Santon,
Ballasalla, Castletown, Ballabeg, Port St Mary and Port Erin. A
further two larger engines were ordered from Beyer Peacock, No.4 Loch
and No.5 Mona. These locos had a greater capacity and were able to
run the whole distance from Douglas - Port Erin without water stops.

Due to the increasing demand during the heyday of Victoria's reign
from holiday makers, a 6th engine was purchased from Beyer, to the
same design as No.s 4 and 5 she was named Peveril.

In 1879, a rival company The Manx Northern Rly, opened a line from
Ramsey in the North to St Johns, thier station lying adjacent to the
IOMR one. This line was 17 miles long, and had some fearsome
gradients, as well as the only 2 viaducts on the steam railway at
Glen Moar, and Glen Wylan (sic). it ran along the west coast of the
island, in places only a few feet from the sea! Finally islanders
could go shopping in Ramsey from Port Erin and return within the day!
The Manx Northern was run by 2 sharp stewart tank engines, 2-4-0's
named Ramsey and Northern, although they purchased a third enigne, a
beyer peacock named 'Thornhill' to the same design as the IOMR ones
in 1880. In the same year the IOMR purchased thier 7th
engine 'Tynwald.'

Expansion in 1885 saw the MNR reach Foxdale, two miles of heavily
graded (1:40 in places) branch line from St Johns, and for this line
and the heavy lead spoil trains from Foxdale mines, a fourth MNR
engine No.4 'Caledonia' was purchased. She was built by Dubs of
Glasgow and is the most powerfull engine on the island, as well as
being the only 6 coupled engine (0-6-0).

The isle of man purchased two more enignes No.8 Fenella and No.9
douglas in 1894, and 1896 respectivley. These were the last of what
was to become known as the 'small' engines. Again heavy tourism saw
the railways running at capacity, Tynwald day specials saw everything
that could turn a wheel, be it coach wagon or van pressed into
service to get people to Tynwald hill in time for the reading of the
Manx By laws, and Kirk Bradden open air church services saw 18 coach
specials being top and tailed out of Douglas.

This carried on till 1905, when the IOMR bought out the Manx
Northern, and created one company, The Isle of Man Railway Company.
1905 also saw the introduction of a new larger type of enigne, almost
identical to the previous locos howveer with a higher cab and bigger
tanks. These locos No.10 GHWood and No.11 Maitland, could run from
Ramsey to Port Erin, and were more powerfull being able to haul
longer trains. In the same year No.'s 4,5 and 6 were rebuilt to the
same size as 10 and 11, and No.'s 1-3 were rebuilt to the same size
as 7-9. This created two distinct sizes of engines....

to be continued....