Why is sand used in locomotives?

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Tags

1. #dramatically
2. #locomotive
3. #control
4. #system
5. #electronic
6. #wheels
7. #increase
8. #emergency
9. #increases
10. #drive
11. #engineer
12. #makes
13. #traction
14. #automatically
15. #trick
16. #starts
17. #train
18. #sprayers