What's the meaning of the phrase 'Hell's bells'?
'Hell's bells' is an expression of anger or annoyance.
What's the origin of the phrase 'Hell's bells'?
The exclamation 'Hell's bells' has been used in both the UK and the USA since at least the mid-19th century. The earliest example of it in print that I can find is from the weekly London sporting newspaper The Era, February 1840. The rather fanciful story concerned a character who had stolen his friend's partridges and replaced them with pigeons, claiming them to be ptarmigan:
To be sure that's a ptarmigan - a sort of white grouse.
Ptarmigan be d----d. Hells bells!
The expression came into common use in the first half of the 20th century and, in 1932, the Australian soldier Joseph Maxwell's used it in the title of the mémoire of his experiences during WWI - Hell's Bells and Mademoiselles. This title was echoed later by George Melly who published his experiences of the Royal Navy in WWII under the title of Rum, bum and concertina.
There's no reason to look for any special meaning of Hell's bells - it doesn't refer to diabolical campanology - the 'bells' are added just for the rhyme. It is an uncommon phrase in that, as well as being an example of reduplication, it is also a minced oath. Adding 'bells' was simply a way of uttering the oath 'Hell' and making it sound acceptable in polite company.
The expression is often extended by other evocative but meaningless additions. In the UK this is often 'Hell's bells and buckets of blood' and, in the USA, 'Hells bells and little fishes' or 'Hells bells and a bunch of parsley'. There are many other variants, in fact almost anything can be added to 'Hell's bells...' as there's no requirement for the addition to make sense.