Bash is a fun-loving logging loco along with his twin Dash, work on Misty Island.
Bash and Dash are mischievous twins who always finish each others sentences. They are playful and eager but get things wrong because they don't have any rules on Misty Island. Bash is a logging loco and runs on oil and wood. 
They were sent to Misty Island along with Ferdinand for not behaving and being really useful whilst working on the Mainland, and because the engines have no rules to abide by on Misty Island, they live for fun and play. Very little work was done until Thomas landed there, and taught the twins that being really useful can be fun too. Bash later wanted to be as brave as Belle the new brave engine and tried to brave the darkness of the night without his lamp but Bash soon realized that he was scared of the dark and needed to overcome his fear so Toby then thought of a way to help Bash overcome his fear. Bash then decided to practice his shunting skills but he fell down a deep hole and Ferdinand came with Rocky to pull him out. Bash is Really Friendly and Really Useful.
Bash and Dash are based on the Bear Harbor Lumber Company's locomotive #1. This type of engine is known as a "gypsy". However, their gearing is on their backs instead of their fronts and their cabs appear much sturdier, as opposed to the "open" cab that their real life counterpart possesses.
- Matt Wilkinson (UK; Misty Island Rescue onwards)
- Kerry Shale (US; Misty Island Rescue onwards)
- Bash and Dash can run on either wood or oil.
- Bash and Dash are the only standard gauge engines in the television series without buffers.
- Dash has freckles, whereas Bash doesn't.
- Bash and Dash are the only engines that have their wheels on the outside of their chassis'. Perhaps because of this, their wheels don't appear to be attached to their underframes.
- Bash and Dash are modified for running on British rail lines. They have screwlink couplings and have been built to run on standard gauge, whereas the real "gypsy" was narrow gauge.