Imperial Airways 1930s ad for the Short Empire flying boat. The Empire was designed in Belfast, first flew with airlines in 1937, and was in active use until the late 1940s. It could carry about 24 passengers over a range of around 760 miles. That was enough for many uses, although it wasn’t able to make trans-atlantic flights until later modifications to extend the range, using extra fuel tanks and inflight refueling. In that configuration it was able to provide trans-atlantic airmail service in the late 30s and 1940s.
It was powered by four radial engines making 910 hp each, with a cruise speed of 165 mph.
Short Empire in the flesh,
Cool vintage interior photos of the Short Empire,
And finally, the cockpit,
For those who’d like to see one of these aircraft in person (albeit a Short Solent rather than a Short Empire), the Oakland Air Museum (attached to Oakland Airport, in the San Francisco Bay Area) has one, and they open it for tours – https://www.oaklandaviationmuseum.org/short-solent-aircraft-tour I’ve been, and it’s very neat – there’s a small tropically themed stand-up bar in the cabin.