You have solved it, well done!
"The "tunnel tigers", who drank, fought, gambled and spent money like water when not risking life and limb in the heart of the hills." https://www.scotsman.com/lifestyle-2-15039/tunnel-tigers-1-608825Here is my riddle, written out in full.
Ben [or Beinn] is not a battleship but you are right in thinking of something very big (and often grey).
Tunnel Tigers were inside several
Bens of which
Ben Cruachan is the most famous, but one of the two
Ben Vorlichs is another well known one. [that is, the tunnels through Ben Vorlich supplying the Loch Sloy hydro scheme]
An extra clue which you may enjoy unravelling - unlike their namesake,
Tunnel Tigers did not drink all the water in the taps. Some of them (for example at
Loch Katrine) did quite the opposite. [that is, they built the tunnels which put the water in the taps of Scottish cities]
More about the Tunnel Tigers can be found in The Scotsman article link above, and see also
https://www.amazon.co.uk/Tunnel-Tigers-First-hand-Account-Highlands/dp/1842820729. The work was dangerous but well paid, and they were also known as "Weekend Millionaires" in towns such as Oban.
Tim