I'm looking for a working example of how to sort my pages in the sitetree by title by default. Ideally I only want to sort child pages of a certain type. In my case I want all my Gallery pages under the parent Portfolio to be sorted Alphabetically by their title.
This is for easy searching in the backend CMS as I know how to sort them in the template.

I have found these examples but not enough to work this out for SS3.1+

http://www.ssbits.com/tutorials/2011/custom-sorting-in-the-cms-sitetree/
https://github.com/silverstripe/silverstripe-cms/issues/848

maybe you want hide those pages from sitetree and use a Gridfield instead?

See this talk about catalog manager module

They need to be displayed as their own pages on the front end.. Are you suggesting that I can control the current pages in a separate gridfield? Or to replace my multiple pages with a single gridfield? I have tried dataobjects as pages via model admin but this wasn't really what I was after and I only need this page sorting and everything would be perfect. Thanks

Click the list icon in the top right when viewing the tree (just the tree, not a page edit form with the tree on the left) to switch to list view. Click 'Page Title' header to order by it.

Thanks Pyromanik I was totally over complicated the idea.. However when I do as you've said the sort order doesn't change! It refreshes and the pages don't change their order... ?

It does by default - at least in 3.1.6

Have you added some other config options to try and make this a thing perhaps?

its strange the filtering works so thats enough but the sort order does not... not sure what I've changed but nothing intentional that would effect page sorting.. thanks for your tip!