For what purpose?

The wire casing is frayed from weather and is very dangerous and it was never put in conduit--It services an 8 plex apt building--just trying to save myself some work

Absolutely not. There is nothing that can or will repair that cable. It MUST be replaced.

Not being in conduit is pretty typical. This type of cable is run exposed. If conduit were used there would normally be individual conductors run.

If this services an 8-plex about your only option is to have a qualified, licensed, insured electrician do this job.
Unless of course you are that electrician.

This is NOT a diy job.

My tenants were freaking when the casing was frayed almost all of it is gone--all other buildings have conduit? don't know why this one wasn't run with it--thank you for your help

I see you are in Ill. Many parts of your state do not allow cable of ANY kind. EVERYTHING must be in conduit. I am not sure how old this rule is though.
If your cable is as frayed as you say it has to be 40-50 years old or more.