Port Dinllaen - A history

Port Dinllaen - A History

Note - This is a fictional “back story” of railways that never existed in this form. But it is based on real rivalries and real proposals that did not come to fruition - truly a railway that “Might Have Been”.


The small, very scenic area of the Llŷn peninsula[1] in rural Gwynedd was a hotbed of railway rivalry that persisted from the great period of railway expansion in the second half of the nineteenth century right up until the Beeching era of the 1960s. The principle driver was control of traffic to Ireland, but latterly it also became part of a fast link between South West Wales, Manchester and Liverpool.

First Phase - a new port    

Port Dinllaen (PD) harbour and station were built in 1850 as the terminus of the North Wales Coast Railway (NWCR) to Carnarvon[2] (original spelling). That railway was engineered by Brunel in conjunction with the much larger Birmingham and Ireland Railway (BIR), a fierce rival to the Chester and Holyhead[3] then being built by Stephenson to provide rapid access from London to Ireland, and gained its charter partly due to skepticism about the technical feasibility of bridging the Menai Straits[4].

The BIR route ran from from Shrewsbury to Carnarvon roughly along the line of Telford’s Toll Road to Anglesey (today’s A5) until Bethesda where it turned and tunnelled into the valley of the Afon Seiont and then followed that down to Carnarvon. There it met up with the NWCR at “Pant Carnarvon” Station. The NWCR then hugged the coast to Porth Dinllaen via several tunnels through the edge of the tri-peaked mountain known as “Yr Eifl” where Snowdonia marches down to the sea.

When he originally engineered the lines, Brunel had in mind using the same atmospheric traction system[5] as in South Devon - resulting in some steep gradients. Particularly impressive was the 1 in 44 grade for 5 miles in the Nant Ffrancon Pass between Bangor and Capel Curig. He did his best to engineer the line to be straight, however, which required some spectacular viaducts in the area of Llangollen.

The port at PD is naturally sheltered on 3 sides and protection was added from northerly winds with a half-mile long breakwater that created a harbor of refuge. The first station at PD simply consisted of a single platform that led to a wooden pier for the mail packet to Dublin.

Second Phase - Enter the Railway Rivals

A spur line from the Chester to Holyhead, the Bangor and Carnarvon Railway, was completed from Menai Bridge to a terminus near the center of the Carnarvon town by July 1852.  

The NWCR and BIR amalgamated as the North Wales and Ireland Railway Company Ltd (NWIR) in 1859 and granted running powers to the Midland Railway from Shrewsbury. The MR was in a pitched battle with their long-standing rival, the LNWR, for the mail warrant for Ireland; the LNWR having just formally taken over the Chester and Holyhead.

In 1863, the Caernarvonshire Railway, an ally of the LNWR, under an 1862 Act of Parliament for a line between Portmadoc and Caernarvon, built a connecting line from the NWIR south of Pont Llyfni at Trefor Junction to Afon Wen where it met the Cambrian Railway. The CR also built a branch line from the NWIR at Pont Llyfni Junction (PLJ) to Nantlle to allow slate from the quarries at Nantlle to bypass the congested Nantlle tramway to Caernarvon send slate via PD.  However, although the Caernarvonshire had running rights over the BIR to Caernarvon, it was thwarted in gaining similar rights from PLJ to PD because the NWIR and Midland wanted to exclude the LNWR from monopolizing the Irish ferry passenger traffic. This meant that the slate trains actually had to reverse at PLJ to go to the quays at Caernarvon instead.

The Carnarvon and Llanberis line was built in 1864 from Llanberis to Morfa, crossing under the NWIR to reach that terminus.  At this point there were three railway stations in Carnarvon but they were not joined together.  The LNWR effectively controlled two of these and had running powers to the third.  

In 1865 the Cambrian extended its single line from Pwllheli to PD as it had originally been granted powers to do in 1862, so that trains could run from South Wales to meet the boats to Ireland without changing at Afon Wen and then PLJ. The mail pier was extended and the Cambrian line platform was placed beyond the NWIR platform but without cover, resulting in many wet trudges from this inferior position to the relative shelter of the NWIR train shed.

Third Phase  - Expansion

In 1870 the Carnarvon Town Line, which was authorized in 1865, was completed to link the town’s three stations. The line provided a junction between Pant and Morfa so that Llanberis trains could access the central Carnarvon Town station, Bangor trains on their way to Afon Wen would pass through the Pant station (renamed Carnarvon Junction), where they would meet trains from Shrewsbury and trains from PD could go via Llandudno Junction to Manchester over the LNWR.

The LNWR added a branch to the Afon Wen line from Chwilog to Brynkir to service a new dairy in 1871.

The limited traffic and expensive working from Shrewsbury coupled with costs of the expansion of the station and port required to accommodate the Cambrian saddled the NWIR with so much debt that it went into receivership in 1886.

Port Dinllaen Lines c 1872.jpg

Port Dinllaen Lines c 1869

Fourth Phase - Consolidation

The bankrupt NWIR was promptly taken over by the Cheshire Lines Committee[6] in 1886 to secure a means to get coal from the Northern coalfields to Ireland for the committee members, bypassing the LNWR monopoly via Holyhead. They built a new line from Wrexham Central to Llangollen to add the northern end of the NWIR onto the CLC main line via Chester in 1887.

Then the NWIR mainline then became the end of the Great Central[7] (Irish Extension) in 1910 when a high-speed line was built from the new Great Western and Great Central Joint Line at Aynho Junction to the former NWIR at Shrewsbury that went via Banbury, Stratford, Kidderminster and bypassed Birmingham. This along with track, signalling and motive power improvements to the Bangor-Llangollen stretch cut the journey time from PD to London Marylebone down by 30 minutes to under 4 hours, instead of well over 5 from Euston to Holyhead via Chester. With similar sailing times to Dublin, this made PD the faster route. At the same time, the LNWR finally gained running powers to PD. To celebrate the Investiture of the Prince of Wales in 1911, the former Carnarvon Junction Station was renamed Carnarvon Central (even though it was really on the outskirts of town!).  The PD port was rebuilt and a second boat pier was added, forming a “U” shape harbour and new goods piers were constructed on the outsides of the U. At last the Cambrian trains passengers had cover on Platform 1b!

Port Dinllaen Lines c 1908.jpg

Port Dinllaen Lines c1910

Coal traffic to Ireland from Port Dinllaen diminished in the First World War and then stopped in 1916 and due to the opening of the DeerPark mines[8] at Castle Comber in County Kilkenny. Live cattle imports for Birmingham increased and race-horse traffic with major trains for large race meetings in southern England like Cheltenham and Ascot were introduced.


In the grouping of 1922, the line from Caernarvon to PD became a joint LNER/LMS line, while that from Carnarvon to Shrewsbury along with the rest of the GCR became LNER with a direct route to London Marylebone, faster than the LMS route to Euston via Chester and Crewe. The line from PD to Pwllheli became part of the GWR like the rest of the Cambrian. The GWR improved the Cambrian line to support express traffic from Manchester and Liverpool along the Cambrian Coast to South Wales via Carmarthen with several double track sections and a new bridge at Barmouth. The LMS owned the ex-Carnarvonshire Railway from Trevor Junction to the Cambrian at Afon Wen. This meant that freight trains to Portmadoc and beyond could bypass the need to work the steep line to Pwhelli. 


At nationalization, the line from Aynho Junction to Carnarvon Central became Eastern Region (ER) along with the rest of the former Great Central, while the line from Bangor to PD was joint Eastern Region/London Midland Region (ER/LMR), the Nantlle branch was LMR as was the PLJ to Afon Wen line. The line from Pwllheli to PD became Western Region (WR). Therefore in the early 50s PD had traffic from 3 out of 4 BR regions. Occasional special through port-to-port trains (both passenger and goods) would run between Dover and PD over the ex-GC lines to allow for direct continental traffic to/from Dublin so visiting SR engines might also occasionally be seen.

Porth Dinllaen Lines - ER-MR-WR.jpg

Port Dinllaen Lines c 1957 


In 1958, BR reorganized its regions and the former ER (GC) mainlines became part of the LMR, while the WR remained as it was. At that time, Shrewsbury Shed (Great Central) became Shed 7A with a sub-shed at Corwen (GC) Banbury (GC) as 7B, Port Dinllaen (ex LMS and LNER) as 7C with a sub-sheds at Pont Llynfi and Carnarvon (GC). This was just as the 7A-7D Llandudno Junction sheds became 6G to 6K.  Meanwhile Port Dinallean (WR) remained as a sub-shed of Machynlleth (6F). Midlandisation took a long time to take hold in this remote corner of the LMR world, resisted by the former ER men and so well into in the early 60s there were still a lot of ex-ER engines and rolling stock to be seen at PD coming from Shrewsbury and Marylebone mingling with the ex-LMS and newer BR Standards.  

In the early 1960s, BR started to experiment with using a new diesel Midland Blue Pullman to provide a twice daily high-speed link from London to Ireland at PD - with a 90 MPH top speed and only two stops at Banbury and Shrewsbury. The trip from PD to London Marylebone was only 3 hours long. A businessman could leave London at 8:30am and be in Dublin by 3pm, or vice versa. This supplemented the Dragon Express trains which would make the same trip in 4 hours.

The Manchester-Swansea through expresses “the Cambrian” still ran, meeting the boats to Ireland northbound and the boats from Dublin southbound.

Once a day a through train Pullman from Dover would run using the old Pullman cars left over from the Golden Arrow when it was electrified in 1958.

Porth Dinllaen Lines - LMR%2FWR .jpgPort Dinllaen Lines c. 1962

Historical Notes

In reality for the Llŷn Peninsula scene,

More generally

But this is a fiction and so anything is possible… The GCR is also a “tip o’ the hat” to the original inspiration for the PDL system - The Buckingham Lines of Rev. Peter Denny. It is definitely needed to allow for ex-LNER locomotives to be seen at PD - and if we go further and assume that the GCR did build its proposed cross-London link for France, perhaps even a Merchant Navy hauled Pullman “Fleche D’Emeraude” might even put in an occasional appearance?

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[2] "Carnarvon - Wikipedia, the free encyclopedia." 2011. 11 Dec. 2015 <https://en.wikipedia.org/wiki/Carnarvon>

[3] "Chester and Holyhead Railway - Wikipedia, the free ..." 2011. 11 Dec. 2015 <https://en.wikipedia.org/wiki/Chester_and_Holyhead_Railway>

[4] "Britannia Bridge - Wikipedia, the free encyclopedia." 2011. 11 Dec. 2015 <https://en.wikipedia.org/wiki/Britannia_Bridge>

[5] "Atmospheric Railway - Isambard Kingdom Brunel." 2010. 11 Dec. 2015 <http://www.ikbrunel.org.uk/atmospheric-railway>

[6] "Cheshire Lines Committee - Wikipedia, the free encyclopedia." 2011. 11 Dec. 2015 <https://en.wikipedia.org/wiki/Cheshire_Lines_Committee>

[7] "Great Central Railway - Wikipedia, the free encyclopedia." 2011. 11 Dec. 2015 <https://en.wikipedia.org/wiki/Great_Central_Railway>

[8] "Deerpark Mines - Wikipedia, the free encyclopedia." 2011. 11 Dec. 2015 <https://en.wikipedia.org/wiki/Deerpark_Mines>

[9] "Disused Stations: Carnarvon Town Line." 2012. 11 Dec. 2015 <http://www.disused-stations.org.uk/features/carnarvon_town_line/index.shtml>