Headbolt Lane station has 3 platforms, P1 & P2 are for Merseyrail, P3 for Northern to Wigan & Manchester, when the service returns to every 15 minutes, & because of the single track section through Kirkby [i don't know why that wasn't doubled too] trains departing for Liverpool will have to wait until after a train arrives in from Liverpool [like what they do at Southport], trains will have something like around a 20 minute layover at Headbolt Lane.
Also, P3 has a different platform construction, this is if or when Merseyrail extends the service to Wigan, P3 can be removed, trains will then use P1 & P2 as through platforms.