In the prototype, turntable bridges come in one piece spans and twin span styles.
The locomotive needs to be balanced on single span bridges which relied on a heavy center pivot and non-load bearing wheels at the ends.
Larger bridges were of the twin span style, with the bridge hinged close the center. On these, the locomotive doesn't need to be balanced, as its weight was divided over the center pivot and heavy rollers at either end running over substantial circular rails inside the pit.
One would assume Big Boy needs to be turned at Cheyenne, so a twin span style would be prototypical.
Interestingly, this article states it was a continuous span, i.e. single span type?
http://www.rgusrail.com/wyuproundhouse.htmlThe thin shape suggest however the ends were load bearing, so the locomotive doesn't necessarily have to be balance precisely.
https://www.youtube.com/watch?v=4rJ2kUDm9Y8https://www.youtube.com/watch?v=UFD07mJQH6k note how fast it rotates the Big Boy and the front pilot overhang
(err, is Big Boy a male or female since steam locomotives are usually referenced as a 'she', much like ships).
'
In the game however, there is no such distinction. There have been problems with turntables reported before, concerning too rapid acceleration/deceleration and an incorrect high center of mass of the locomotive to be turned.
EricMopar could very well be right, large steam locomotives and 'empty' tenders could lead to imbalance. And since Big Boy is considered two engines by the sim, the distribution of mass might be even more off.
You could experiment with FEF, Challenger and Big Boy and find out which gets thrown off.
Perhaps the rotational speed of the bridge can be lowered as well?
The tracks don't necessarily have to be visually aligned for the locomotive to be able to enter or leave the bridge. When in "9" view the blue track line matches, the game thinks the tracks are aligned.
Posted: Sat Sep 03, 2016 11:39 am
