Freight Operations - Private Owner Stone & Lime
Building Stone and Road Stone
Most building stone was
shipped in railway company vehicles but some was transported in PO wagons,
usually heavily built low sided types. Before the second world war concrete was
not as widely used as today and kerb stones, paving flags, window and door
lintels and even door steps were commonly made from stone (usually granite). PO
stone wagons, generally low sided affairs, might appear (particularly if
transporting large blocks) in a siding near a road or building construction
site.
In 1815 the Macadam road appeared, this had a top coating of
small stones and in N 'chinchilla sand' from the pet shop makes a passable
representation. The top coating would typically be granite or (more likely)
limestone although any rock that could be locally produced was used.
A
quarry is a big thing, but many had no direct rail connection and used road
carts and later lorries to deliver chippings to the local railway siding. No
special facilities would be required for this, just a raised bank to allow the
tip carts or tipper lorries to load the railway wagons. The sketch below was
made from a photograph taken in the 1930's showing a steam tipper lorry (note
the screw drive tipping mechanism) loading railway wagons on such a bank.
Fig___ Sketch of stone loading bank used for chippings
Similar arrangements have been used to load PCA stone hoppers
and HEA coal hoppers, although the bank for these was rather higher. A more
modern version of the same basic idea is shown below. This was in use in the
late 1970's, again its a simple modelling option requiring only a siding along
the rear of the layout. As well as the structure shown there would probably be
a weighbridge on the track approaching the hopper and a couple of huts to serve
as a stores and an office.
Fig___ Sketch of loading point with
hopper feed
The dimensions shown are for N Gauge and again similar
installations have been used with modern air braked rolling stock. More
information on these loading facilities, including more elaborate designs, will
be found in the section on Lineside Industries.
In the early 20th century there was an increasing demand for 'tar macadam' roads, in effect these were the existing Macadam road surface coates with limestone chippings coated in gas works tar. Generally the tar was heated on site and applied to a conventional macadamised road but some coated chippings were
produced and these were shipped by rail. See also Appendix One - Roads and Road Works.
Limestone is the best material for tarred
roads as the tar sticks well to this type of rock and stone chippings have been
a regular cargo on the railway ever since. You would occasionally see
a tarred chippings plant at the loading site for a quarry. These were neither
large nor sophisticated, a simple corrugated iron shed similar to a goods shed
would serve, although it would have a largish 'industrial' chimney as the tar
was heated to make it flow.
Fig ___ Simple aggregate loading point and tarred chippings plant
See also Lineside Industries - Open Cast Mines & Quarries
The railways were not obliged to carry tarred stone as it would contaminate
the wagon so tarred chippings were commonly moved in metal bodied PO wagons
(the former Mike Bryant-Precursor Models iron PO wagon would be ideal for this). This
traffic was never very common, it lasted from the early 1920's to the late
1930's.
The wagon shown below, sketched from a photo in Peter Mathew's book on PO Wagons (see bibliography) is an all steel wagon equivalent to the three plank design built in 1923 to the then new RCH specification. The livery is that of the wagon builder although it may have operated in this livery for a time before being repainted in the owners colours.
Fig ___ PO steel bodied road stone or tarmacadam wagon
There are a couple of photographs of such a facility in the late Mike
Lloyd's book The Tannant Valley Railway. I do not have my copy to hand bur from memory the siding was a dedicated private siding at
some remote location, the loading bank was long enough to hold perhaps ten
wagons in the open and a further three or four could fit inside the tin shed
covering the tarred chippings plant at the buffers end of the siding.
Limestone and lime (produced by cooking limestone) were both shipped in PO
wagons, usually owned by the quarry producing the stone. Broken limestone was
used in large quantities by steel works and rakes of between ten and twenty
wagons (all owned by either the quarry or the steel works) would be seen
carrying this material.
Lime was usually made at or close to the
quarry and was shipped loose or bagged by the single wagon load, as it would
contaminate the wagons the railways were not obliged to carry it (although they
often did). The PO wagons used for lime were either fitted with a roof (usually
peaked) or with a horizontal bar to support a tarpaulin. Lime was mainly
produced in fairly large kilns, often with a siding running up close to the
sides of the kiln, these are discussed under Lineside Industries. Some lime
from smaller quarries was however carted by road to a remote siding. I believe
that where this was done a covered loading area was the norm.
Steel
works consumed a lot of lime and it was widely used in agriculture where it was
spread on acid or 'sour' soils. Other uses included antiseptic preparations,
tanning leather, making chocolate and sugar refining and even for making
perfume. It was used in the manufacture of caustic soda and as a water
softening agent in hard water areas. Lime wagons can therefore appear on almost
any layout.
In the mid 1990's there was a working for agricultural
lime, moved in a rake of seven un-sheeted HEA hoppers, which surprised me as I
thought lime was always covered over in transit. The lime was only loaded to
within about eighteen inches of the top of the sides, possibly to reduce the
amount blown out of the wagon or possibly because it weighs more than the coal
the wagons were designed for (I am not sure which).
Lime was also
essential for making 'bleaching powder' which was vital to the cloth industry.
Although bleaching powder itself was rather unpleasant stuff I have found no
record of wagons built to carry it, however as bleaching powder was very
valuable the legislation on charging allowed the railways to earn a healthy
profit on carrying it (beaching powder was selling for over a hundred pounds a
ton at the time the railways were first being built). Bleaching powder was
shipped in wooden barrels, heavily stained white, and the vans used to carry it
would have some staining round the doors where they had been loaded.
Limestone is Calcium Carbonate (CaCO3) and lime is Calcium Oxide, CaO. If
you add water to lime you get slaked lime, calcium hydroxide Ca(OH)2. Slaked
lime mixed with water and sand is mortar, used in building brick and stone
buildings, the lime reacts with carbon dioxide in the air to form calcium
carbonate (limestone).
In quarries who's business was mainly the
manufacture of lime the poor quality rock was often crushed and sold as road
stone as a side line. Most of this road stone was sold for local use and most
was taken out by road but short rakes of wagons carrying this stone might be
seen in the vicinity of the quarry, in transit through the system or being
unloaded in a goods yard close by the road works.