In that use, "some" means "about" or "approximately". The number was estimated to be about 60.
Interested in Language
2) formally decline to vote either for or against a proposal or motion
forty-one voted with the Opposition, and some sixty more abstained
Rephrase, please, the part in bold so that I can understand it.
"Some a particular number more"
Actually, the entire group was more than that. We are not told how many voted with the government, only how many did not vote with it.