This is just a suggestion to give your players a possible puzzle to solve on their own if they want to get creative:

• Perhaps there is a hidden cache of orbs in the train car, but a bunch of SCP-001-As surrounds it; causing your group to sneak around it.
• Could there be a way to make the Sun's UV rays less fatal without tampering with the orb?
• Maybe players who are good at programming could fit the orb themselves if they can find some tools.
• If you want to get a little silly and break with the SCP canon, maybe there is some special sunscreen or something that could be used to make the monsters friendlier.

All this to say that train cars can become a lot more fun for players if they are given a wider number of options when tackling the problem. Admittedly, I don't know a lot about the SCP Foundation's canon, but I think there is a lot of cool stuff here that you could definitely have some fun with.

Hope this is helpful. Keep up the good work!