According to Realtime Trains the route and timings were;
<p>Swansea [SWA]...................1429...................1428 3/4...................RT
Swansea Loop East............1430 1/2.............1430 1/2....................RT
Neath [NTH]..........................1439 1/2/1441....1439 1/4/1442............1L
Briton Ferry [BNF]...............1443 1/2.............1443 1/2....................RT
Port Talbot Parkway ..........1447 1/2/1449...1448/1450 1/4...........1L
Margam Moors Junction...1454...................1454 1/4....................RT
Stormy...................................1457...................1457 1/2....................RT
Bridgend [BGN]...................1501/1502 1/2...1501 1/4/1502 3/4...RT
Pontyclun [PYC]...................1511.....................1511 1/2......................RT
Cardiff Central [CDF]..........1522 1/2/1526..1522/1527..................1L
Marshfield.............................1532 1/2.............1534............................1L
Ebbw Junction.....................1535...................1537 1/2.....................2L
Newport [NWP]....................1538/1540.........1539 3/4/1542 1/2...2L
Maindee West Junction....1541 1/2..............1544...........................2L
Llanwern West Junction....1543 1/2.............1546 1/2.....................3L
Severn Tunnel Jn ...............1549...................1552 1/4.....................3L
Severn Tunnel West...........1550...................1553...........................3L
Severn Tunnel East............1553 1/2.............1556 1/2....................3L
Pilning [PIL]...........................1554 1/2.............1557 1/2.....................3L
Patchway [PWY]..................1558 1/2.............1600 1/2....................2L
Bristol Parkway [BPW]........1600 1/2/1603..1603/1606................3L
Westerleigh Junction.........1607 1/2.............1611.............................3L
Hullavington.........................1614 1/2..............1619............................4L
Wootton Bassett Jn............1621....................1625...........................4L
Swindon [SWI]......................1627 1/2/1630...1631/1633..................3L
Uffington (Oxfordshire).......1638...................1641............................3L
Challow..................................1639...................1643...........................4L
Wantage Road.....................1641....................1645 1/4.....................4L
Steventon..............................1643 1/2.............1646 1/4.....................2L
Milton Junction....................1644 1/2.............1647 1/4.....................2L
Foxhall Junction..................1645 1/2.............1648 1/4.....................2L
Didcot Parkway [DID].........1646 1/2/1648..1649 3/4/1652.........4L
Didcot East Junction..........1649...................1652 1/4.....................3L
Moreton Cutting..................1650...................1652 1/4.....................2L
Goring &amp; Streatley .............1654 1/2.............1657...........................2L
Reading High Level Jn......1700...................1701.............................1L
Reading [RDG].....................1702/1704.........1703/1705 1/4............1L
Kennet Bridge Junction....1706...................1706 1/4....................RT
Twyford [TWY].....................1709...................1710.............................1L
Maidenhead [MAI]...............1712 1/2..............1712 1/2.....................RT
Slough [SLO]........................1715 1/2..............1715 1/2.....................RT
Stockley Junction...............1719 1/2..............1719...........................RT
Heathrow Airport Jn...........1720...................1719 3/4....................RT
Hayes &amp; Harlington ...........1720...................1720 1/4....................RT
Southall West Junction......1720 1/2.............1720 1/2....................RT
Southall [STL].......................1721....................1721 1/2.....................RT
Southall East Junction.......1721....................1721 1/2.....................RT
Hanwell Bridge Loop.........1721 1/2..............1721 3/4....................RT
Hanwell [HAN].....................1722...................1722 1/4....................RT
Acton West...........................1723...................1724............................1L
Acton Main Line [AML].......1724...................1724 3/4...................RT
Friars Junction.....................1724 1/2.............1725..........................RT
Old Oak Common West....1725...................1725 1/2....................RT
</p>
Old Oak Common East......1725 1/2.............1726..........................RT
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