Swindon is wrong I think, because both times I've been there, there has been a 150 or a 158 waiting in a West-facing bay on services down the Kemble line forgive me if I'm wrong, but is Seven Kings bi-di? Because twice I've been on a Southend service which has trundled along the metro lines until Seven Kings whereupon it has crossed over to the London-bound track and gone through that platform and then after the station has crossed over to the fast tracks. Also I'm pretty sure I've been through there wrong line on the fast lines as well