Covered vans followed, initially for carrying cattle but later for any kind of goods that needed to be protected from the weather during transit.

Indeed, special wagons were built for many different commodities such as gunpowder, china clay, motor cars, boilers, long girders, sheets of glass, cattle, fruit and fish.

Some ballast hoppers were given vacuum brakes in December 1903, and some general goods wagons were constructed with them from 1904 onwards, although unfitted wagons (those without vacuum brakes) still formed the majority of the fleet on 1 January 1948 when the railway was nationalised to become a part of British Railways.

[6] In common with most other British railways, goods trains were coupled together by a large three-link chain between sprung hooks on each wagon.

More common on GWR wagons was an instanter coupling, in which the middle link was specially shaped so that they could be shortened when in vacuum-fitted trains.

[6] Wagons were painted brown in the early years of the GWR,[8] but this changed to red before the end of the broad gauge in 1892.

[9] The owner of the wagon was identified by 'G.W.R' painted in small letters on the underframe or bottom plank of the body.

[10] The earliest wagons were of an open type, essentially a four-sided box with a drop-down door in each side carried on four or sometimes six wheels.

[11] Many early wagons were built with semi-circular raised ends that could support a tarpaulin cover or 'tilt'.

A number of longer wagons were constructed for special traffics such as metal tubes or lengths of timber and given the telegraphic code 'Tube C'.

[11] Diagrams N23, N24, N31 and N32 were large 20 ton iron opens built for coal traffic, many of which were hired to specific collieries or coal merchants at cheap rates as these were more efficient for the railway to haul than the 12 ton wooden vehicles that these businesses generally owned and operated themselves at the time.

[13] Early wagons were always open at the top, but from the 1860s covered vans were built in ever increasing numbers.

[16] Post grouping in 1923, of the 282,000,000 imperial gallons (339,000,000 US gal; 1.28×109 L) of milk transported by rail by all four national railways companies, the GWR had the largest share of milk traffic, serving the rural and highly agricultural West of England and South Wales.

Introduced from 1926, milk tank wagons were initially built on two-axle GWR chassis, and from 1936 on three-axle.

Typically weighing 25 long tons (25,000 kg) when loaded with 3,000 imperial gallons (3,603 US gal; 13,638 L) of milk product, it resulted in a wagon that was as heavy as an express passenger coach.

From 1931 specialised flat wagons known as 'Conflats' were built with special fittings to carry containerised goods.

Similar but more lightly constructed vehicles for carrying ordinary carts, lorries and motor cars were coded 'Loriot' or 'Serpent'.

Later construction was all to the large size but with a moveable partition that could reduce the capacity if that was what a farmer required; if cattle were left with too much space they would hurt themselves if they fell over when the train was in motion.

They were allocated diagrams in the N series alongside ordinary mineral wagons for revenue earning traffic but were identified by a large 'LOCO' painted on the sides.

[30] These were originally just ordinary flat trucks run without a load, but in later years a number of old wagons were kept for this purpose and given diagrams L21 to L23.

These wagons carried a distinctive asymmetrical toolbox and usually had their depot name painted on this.

Full length footboards and hand rails allowed the guard or a shunter to ride on the outside during shunting movements.

[10] With very few exceptions, all GWR wagons were allocated a page in a diagram book showing their major dimensions and characteristics.