workhorse

noun

1. A horse used primarily for manual labor; a draft horse.
2. (broadly)Someone or something that does a lot of work; something or someone who works consistently or regularly.

   “Those old machines are not very glamorous, but even 20 years after their introduction, they are still the workhorses of the industry.”

   “Captain Harry Kane was the workhorse and creator, while Sterling and Rashford provided the finishing flourishes that put England in dreamland at the interval.”

   “"Class 08s have been the workhorses of ports, distribution centres and depots across Britain's railway for more than 60 years," said Positive Traction Director Alistair Gregory.”