Full time amount of work in part time hours

[Buzybee92734]

I've recently started a new job in a school. I worked full time at another school and saw a role at this one, which was also advertised full time. I explained I needed part time and got a 20 hour contract and job share. Perfect.
Its a lovely place and im settling in well. But I've just been given my responsibilities and compared it to the original job advert and its exactly the same! Nothing has been removed even though im working 18 hours less a week. Why have they done this and what do I say? I dont want to start off on a bad foot but also I dont want to take on a full time work load as I know it will drag me under. I have alot going on in my personal life and cannot let my work overtake my life. That's why I've gone part time .
Colleague told me the person I replaced left because of the workload (same one given to me) and she was full time hours!
Im now feeling very anxious.
Please bare in mind that a school is a whole different working world to most places. There's no HR, no mention of a union, your expected to work extra hours for free and attend out of hours events etc for free.
Any advice?

Also there is always going to be a certain amount of jobs in the office and usually there is only 2 staff members so everyone has to take on alot which I understand

But why allow me part time hours if the work cannot be accommodated?
There is also absolutely no time for training as the other staff so busy so im clueless on some and some parts I have no experience in at all so dont know how i can suddenly just do something that i have never ever done before. They are aware of my experience

There absolutely are unions for support staff in schools. Unison, GMB and NEU all say they are for school support staff. Have a look and see which one looks best to you.

If you’ve been hired as a job share who are you job sharing with? Have you asked.

You need to ask for training on stuff you don’t know how to do. Yes people are busy but teach a man to fish and all that.

In simple terms OP you need to be more assertive otherwise you will get in a pickle.

I dont want to seem like im moaning or being awkward before I've even began but I can just see what's coming!
The person doing the afternoons is just doing simple easy stuff! None of my workload at all!

I was a sahm for a long time and took any job to get back in to work, now im in schools which I love
But this is my 3rd job in 3 years due to that which I dont think looks good to future employers! I don't want to have to leave here aswell

Surely your job share partner is sharing the workload?
Join a union ... unite or unison.

Why don’t you at least start the job first and experience the workload and then if an issue - raise it