In 1932 the Earl of Plymouth had to forego his royalty payments to help keep the dock in business .
Penarth Dock finally closed in 1936 after annual exports had dropped to 685,000 tons .
In 1932 the Earl of Plymouth had to forego his royalty payments to help keep the dock in business , but Penarth Dock finally closed in 1936 after annual exports had dropped to 685,000 tons .