After the idyllic period in Roos it is believed Tolkien returned to Thirtle Bridge Camp, which is approximately 1¼ miles south-east of Roos. On some detailed old maps Thirtle Bridge is marked, but no one lived there before World War One, it was simply a bridge over the Tunstall drain on the road to Withernsea. The nearest place of habitation before the war was an isolated farmhouse at Renish. However, for the duration of hostilities a temporary camp was installed on the higher ground above Thirtle Bridge catering for 1,500 men. A rough idea of what was present at Thirtle Bridge during Tolkien’s time may be gleaned from a local paper which advertised the auctioning off of “the whole of the existing hutments” of both Thirtle Bridge and the smaller Dimlington site, which consisted of: “about 40 sectional wooden huts of various sizes, 50 armstrong sectional canvas huts, bath houses, cook houses, several brick buildings, cooking ranges, boilers, a No. 5.0 Bno independent boiler and connections, and 1.25 inch iron piping.” Very little survives of the camp. However, the southernmost section of the present Mona House is believed to incorporate the Officer’s mess and the footprint of the former cookhouse survives as a corrugated barn. Despite the meagre evidence Dave Mitchell, a model maker, has examined the ground and reconstructed as far as is possible what the camp may have looked like. This model can be found in the nearby Withernsea Lighthouse Museum.
Of course Thirtle Bridge was an army camp, and Tolkien was there at a time of war, but when not actually engaged in repelling Zeppelin attacks or involved in physical activity time hung heavy on the hands of the “inmates,” so Tolkien almost certainly had time to mull over his emerging mythology. The Tolkien Estate informed David Robbie, the Staffordshire historian, that a photograph of Tolkien in an army camp published in The Tolkien Family Album (p.38) has Tolkien’s writing on the back which says: “Self in Hux’s and my cubicle, Withernsea (Thirtle Bridge) 1917”, so this photo actually depicts Tolkien among the inside of a Thirtle Bridge hut! Hux must refer to Tolkien’s long-time comrade and friend Leslie Risdon Huxtable, with whom he had shared quarters on Cannock Chase. Huxtable was another signalling officer, and was believed to be Tolkien’s deputy at one time, ready to take over if anything happened to Tolkien. Garth mentions him as being based at Tunstall Hall after receiving an injury in France, and being at the Minden Dinner with Tolkien on 1st August 1917. Another photograph from the same source revealed its secrets only in November 2015. This photograph on page 41 depicts a very thin uniformed Tolkien on a beach with Edith. When Phil Mathison wrote his book he assumed that this was taken on Hornsea beach. However, on reflection he considered that Withernsea may have been the most likely location, so he wrote to the Tolkien Estate in August 2015. They replied that on the back of the photograph Tolkien had added the following words: “Withernsea/July (?)/1917./ taken by L.R. Huxtable”.