15,000 miles of scaffold tubing
... that in 1940, England was protected by 15,000 miles of scaffold tubing?
... that in 1940, England was protected by <b id="mwBA4"><a href="./Admiralty_scaffolding" id="mwBA8" rel="mw:WikiLink" title="Admiralty scaffolding">15,000 miles of scaffold tubing</a></b>?