Hello
According to thelogic that where six coupled axles pass, five axles can also passtwice, Union Pacific at the end of the 1940s set up and had ALCObuild an oversized Big Boy, with an extra axle per carriage.
The Mallets with 5coupled axles did not have great success both in the ATSF experimentsand at the Virginian, where these machines were mainly used in pusherservices.
The UP, however, hadother armament and other service requirements. If 2x4 axes were fineand 6 managed to pass without unhinging the rails, then a 4-10-10-4could do its job as well.
And indeed he did,albeit for a short time.
In fact, startingfrom the 1950s UP implemented a plan of forced dieselisation,eliminating steam from its network towards the end of 1957, whenprecisely this "Bigger Boy" was decommissioned anddemolished.
The name, as usualin the UP house, came up with the usual apprentice boy who with chalkhad become the nightmare of the company's marketing departments.
In fact, while theexecutives spent entire days trying to find a "right" name(eg Challenger, Mohawk, Northern, etc.) he used his chalk to writewhat was going on in his head on the smoke chamber of the newlyarrived cars.
The trouble was thathe also nailed it...
Ciao ALMorgan
According to thelogic that where six coupled axles pass, five axles can also passtwice, Union Pacific at the end of the 1940s set up and had ALCObuild an oversized Big Boy, with an extra axle per carriage.
The Mallets with 5coupled axles did not have great success both in the ATSF experimentsand at the Virginian, where these machines were mainly used in pusherservices.
The UP, however, hadother armament and other service requirements. If 2x4 axes were fineand 6 managed to pass without unhinging the rails, then a 4-10-10-4could do its job as well.
And indeed he did,albeit for a short time.
In fact, startingfrom the 1950s UP implemented a plan of forced dieselisation,eliminating steam from its network towards the end of 1957, whenprecisely this "Bigger Boy" was decommissioned anddemolished.
The name, as usualin the UP house, came up with the usual apprentice boy who with chalkhad become the nightmare of the company's marketing departments.
In fact, while theexecutives spent entire days trying to find a "right" name(eg Challenger, Mohawk, Northern, etc.) he used his chalk to writewhat was going on in his head on the smoke chamber of the newlyarrived cars.
The trouble was thathe also nailed it...
Ciao ALMorgan
