GWR pagoda platform shelter

The archetypal Pagoda Platform Shelter was a distinctively-shaped corrugated iron structure used by passengers waiting at railway stations in Wales and southern England. 
Origins.
In Britain Pagoda shelters are associated with the Great Western Railway (GWR) who introduced them in 1907 and erected a patchwork of them across their network. They were manufactured by an outside supplier and delivered in kit form. They could therefore be assembled offsite, delivered on standard well wagons and craned into position, or assembled onsite, according to circumstances.
The GWR opened its first "Haltes" on 12 October 1903, anglicising the name to "Halt" in 1905. They were prime candidates for Pagoda shelters, but the market was crowded: finance, tradition, knowledge, skills and materials to hand meant that some lines had pagodas aplenty, some one or two and others none at all. The Bala to Ffestiniog Line in upland Wales, for example, had six halts erected at remote, virgin sites between the World Wars, and had pagoda shelters, but , , and had shelters with other designs.
Opening halts and standardising cheap to install and cheap to buy infrastructure in the face of competition firstly from trams, then buses and ultimately cars overlapped with other initiatives such as the railmotor.
Spread.
Pagoda shelters were generally associated with branch lines, but many were erected next to regional arteries and some were erected next to main lines; being an example on what was and remains a high speed route out of .
Specifications.
Although they were renowned for their shape, their greatest virtues were their cost, simplicity and durability, coupled with the fact that the GWR "took them seriously". They were built to precise working drawings with materials to exact engineering specifications. The example installed at the remote , for example, had a roof made of "No. 18 SWG Galvanised 3 inch Corrugated Sheeting [...] with a floor of specially prepared timber."
Suitability.
Many small halts used wooden platforms on a timber frame, rather than masonry or earth. The pagoda shelter could be used for these because of its light weight.
Platform configurations.
A pagoda shelter was typically provided for each platform, as, for example, at . As the halts where they were used were mostly on single-track lines, there was only one shelter, though had only one platform with two pagoda shelters. Stations such as and Ruislip Gardens with two platforms, had two, one on each platform, as did . and had two platforms but a pagoda shelter opposite the masonry station building only. Perivale Halt had several on each platform. Defiance Halt (later Defiance Platform) had one on each platform initially, but two more were added to the Up platform during the station's life. had three platform faces with a pagoda shelter only on the most southerly.
Variations.
Most pagoda shelters were simple structures with one doorway leading into one room. At , however, the station building was a "Pagoda Building", with three doors and four windows facing the platform and rooms inside for different purposes. still has a pagoda shelter which used to incorporate a "lean-to" staff cabin at the Aberdyfi end. The lean-to appears to have been incorporated into the overall building since it was de-staffed. The shelter differs from most pagodas in that it is either built of or clad with timber.
Although the standard pagoda shelter measured by , they could be erected to different dimensions, occasionally at the same location, such as .
Uses.
The shelters were mainly used by passengers waiting for trains, but at least two - at and - were "Pagoda lamp huts", whilst one at was a shed. and each had a "Pagoda bike shed". Pagoda huts existed next to Weymouth Junction signalbox, and in station goods yard, neither was for passenger use. A Pagoda shelter was erected at right angles to the track next to the down platform at , unsigned and painted black; research continues into its purpose. It was still there in 1989, 28 years after the station closed and long after all other buildings had been demolished.
Other railways' pagoda shelters.
The GWR did not have a complete monopoly of pagoda shelters; , and on the former LSWR branch near Bodmin in Cornwall had one each, and the Highland Railway had at least one, at the remote Borrobol on its main line to Wick. In the USA Pagoda shelters were adopted on a grand scale by at least one railroad.
The present.
By 2015
Most, however, have been demolished