Volume Ten - Pre-Victorian to the Present Day - Even more aspects - Investigation into the Condition of the Ely River Subway 1991 . . .

Despite these precautions there were two inundations during the tunnelling of the Subway, the first in November 1897 on the north bank of the river and again in December 1898 beneath the south bank. Both inundations resulted in a significant ingress of soil and water into the tunnel amounting to approximately 1000 cubic metres in total. This was equivalent to 30% of the total volume excavated from the tunnel and therefore would have caused considerable delay. Apparently no deaths resulted from these catastrophes and the Subway was constructed without loss of life. The last ring was placed in September 1889 and the Subway was officially opened on 14th May 1900.

With the decline of the Docks in the 1930s, the Great Western Railway Company who had become the owners of Penarth Dock as a result of the Railways Act of 1921, found it necessary to close the Subway temporarily in July 1936. The revenue from the tolls for that year provides an estimate of the usage of the Subway as 50 people per day. The Subway was reopened during the Second World War as a result of the reopening of Penarth Dock. However following complaints of vandalism and insanitary use, the Subway was finally closed on 30th September 1963 by the then owners, The British Transport Docks Board being the successors to the British Transport Commission who were formed when the Railways were nationalised in 1948.

In 1976 approximately 75m of the cast iron lining at the Penarth (Southern) end of the Subway were removed to be sold for scrap and the excavation was backfilled. The remaining section of the Subway was flooded and the resulting water level has remained virtually constant at approximately 55 metres from the north portal of the Subway.

Following the recent Portway Marina development around the entrance to the old Penarth Dock nothing of the Subway or the toll house remains visible on the surface at the southern end. The remains of the toll house can still be seen on the north side within the compound presently leased by the Penarth Motor Boat and Sailing Club from Associated British Ports.

The Subway is presently under the ownership of Associated British Ports, who were formed following the privatisation of the British Transport Docks Board in 1982.