The Orion class nearly received a larger gun than the 13.5-inch weapon eventually selected. An Elswick 14-inch/45 option was available, but it was less proven and fewer firms could manufacture it. The 13.5-inch gun offered lower development risk and a broader production base, and became a reliable weapon in service. Capital-ship procurement favoured reducing those risks because the consequences of failure included the lives of the crews.
Notable Point · 43:31-45:20
Why the Orion class kept the 13.5-inch gun
A proven design and a broader manufacturing base favoured the 13.5-inch gun over the available Elswick 14-inch/45 option.