Right up until relatively recently the railway system in the UK had what was called "Common Carrier Status" which basically meant they were compelled by law to move anything that was presented to them. That's anything from a single sewing needle to a 500 ton electrical transformer and everything in between. Boxes of day old chicks, pianos, corpses in coffins were all moved up and down the length of the country at great inconvenience to the railway. This obligation was removed as part of the British Railways modernisation plan reforms in the late 1960s but before that the railway had to keep thousands of different types of wagons standing by on the off chance including, yes, some for moving elephants.I must defer to the classic insider understanding possessed by @escargot1 on this, but I understand that at one time it was possible to send even an elephant as letter-post via the Royal Mail (for reasons of speed and favoured handling). My fractured recollection regarding this is that this was an entirely-seperate stratum of superior speed than mere First Class or Second Class.
Naturally, common-sense would dictate that an elephant being sent via Royal Mail would normally travel as Parcel Post. Probably.
... Brian Robson wants to contact Paul and John - he can't remember their surnames - who helped him get out of Oz. Brian, from Cardiff, was 19 years old when his two friends helped nail him into a crate so that he could mail himself from Melbourne to London. He couldn't afford the air fare but he was desperate to get home. ...
The Welshman who mailed himself home from Australia in a box
He'd only just arrived in Australia from Wales, but teenager Brian Robson quickly realized that he'd made a big mistake by emigrating to the other side of the world.
Unfortunately the homesick 19-year-old didn't have the money to cover the cost of abandoning the assisted passage immigration scheme he'd traveled with in 1964, as well as his return flight home.
After realizing his options were pretty limited, Robson, from Cardiff, hatched a plan to smuggle himself onto a plane in a small box and travel back in the cargo hold. ...
Speaking of Robson ... This CNN article provides a detailed account of his desperation to get home from Australia and the trials he endured during his time in a crafe.
FULL STORY: https://edition.cnn.com/travel/article/welshman-who-mailed-himself-home/index.html
There's a couple of things in his story which don't quite add up: ...
From the Archives, 1965: Stowaway’s box seat in airliner
First published in The Age, May 18, 1965.
If Brian Robson, Melbourne’s air-borne “migrant in a box,” had contacted the Immigration department when he came out of gaol in Brisbane on April 27, he would now be back home in Cardiff, Wales — without cost.
Robson’s friends discovered in Melbourne yesterday that his highly dangerous trip home was unnecessary.
The Immigration department had already decided to send him back to Cardiff, Wales, free of cost. ...
An Immigration department spokesman said Robson arrived in Australia by air from Cardiff, on July 8, 1964, as an assisted migrant recruited by the railways.
“Due to an unsatisfactory record in his short time in Australia, and as there seemed little prospect of his successful settlement, Robson was to be offered repatriation to Wales,” he said.
“Before this decision was conveyed to him he apparently left Australia.
“Had he reported to the department after leaving gaol in Brisbane in April, as he should have done, Robson would now be home in Wales,” the spokesman added.
It was reported from Brisbane last night that Robson completed a five months sentence for false pretences on April 27.
(Emphasis added)... But instead of being placed on a direct 36-hour Qantas flight from Sydney to London, the crate was shipped by Pan Am.
And at Los Angeles airport yesterday, cargo officials heard knocking and saw a flashlight shining out of the crate.
Inside, cramped and too weak to walk they found Robson — 92 hours and 8000 miles after he had been nailed into the crate in Melbourne.
When he was unloaded in Los Angeles on Saturday night he didn’t know where he was. ...
Robson was nailed into the crate at his Albert Park (Victoria) boarding house on Friday. He expected to be consigned to London via Qantas.
Instead, he was flown to Los Angeles by Pan American Jet and discovered inside the crate by a freight worker at Los Angeles airport.