Northamptonshire Ironstone Railway Trust

Hunsbury Hill Road, Camp Hill, Northampton NN4 9UW. Tel: 01604 702 031

15 Oct 2017
Submitted by Carl Hinton

Our desire is to restore brakevan 950061 to its original livery. When it was completed 29th October 1952 in the Derby works it would have been painted bauxite. The historic composition of this paint is given below.

The colour or shade of  'bauxite' changed with time, although basically a matt brown colour some wagons appearing to be red/brown, while others are an earthy brown. Later livery rule changes and occasional painting mistakes saw variations to the original plans, however BR also made strides towards operating all trains as fully braked and eliminating the grey unfitted wagons.

Aluminium is the most abundant metal on Earth. Despite this, it is expensive, largely because of the amount of electricity used up in the extraction process. Aluminium ore is called bauxite. The bauxite is purified to yield a white powder, aluminium oxide, from which aluminium can be extracted.

Known formally as bauxite residue, red mud is the noxious by-product of the Bayer process for extracting aluminum from bauxite ore. Aluminum mining leaves behind a staggering 120 million metric tons per year of the salty, highly alkaline, heavy-metal-laden material, according to the International Aluminium Institute, a London-based trade organization. The aluminum industry has long tried to find ways to recycle the environmentally problematic red mud. But so far there have been few safe and economical large-scale applications.

In the Bayer process, strip-mined bauxite is treated with hot caustic soda (sodium hydroxide), which selectively dissolves aluminum from an array of other mineralized metals. The end product is alumina, Al2O3, which is the feedstock for producing aluminum metal.

RedmudBut for every ton of alumina extracted, more than a ton of red mud is produced. Bauxite processors recycle the caustic soda and pump the residual red sludge into huge settling ponds. When as much water is removed as possible, the material can be chemically treated to lower the pH and planted over with vegetation.

The scourge of red mud burst into the public’s eye in October 2010 when a settling pond in Hungary ruptured. A flash flood of red sludge gushed through several small towns, killing 10 people by drowning and injuring more than 100 others by burning their skin and irritating their eyes and lungs.

Unfortunately it would not be legal for us to make our paint according to the original recipe (shown below). The resultant paint would be today considered toxic.

Instead we will simply match the P127 freight-wagon pantone - html #7a2214 or RAL 3011

Bauxite

MIX 2 BAUXITE PAINT (UNDERCOAT)

Boiled linseed oil 8lb
White spirit 6-10lb
Liquid drier 2-4lb
Bauxite residue in oil 82lb

MIX 2A BAUXITE PAINT (SECOND COAT)

Mixture number 2 100lb
Black in oil 6lb

MIX 2B BAUXITE PAINT (FINISHING COAT)

This is not shown in the specification, but its probable composition is given below
Mixture number 2A 90lb
Mixing varnish 10lb

 

 

References

The LMS Wagon : R J Essery & K R Morgan