Bangor–Caergeiliog line type
Contents
Overview
A double-circuit 33 kV tower line formerly ran between Minffordd outside Bangor (Gwynedd, North Wales) and Caergeiliog on Anglesey (Ynys Môn), constructed using—judging entirely on appearance alone—what appears to be a late if not the final variant of J L Eve’s lineage of 33 and 66 kV towers.
The Open Infrastructure Map still shows Minffordd portion of the line as double circuit on steel towers (as of October 2026), but the entire line was at some stage reduced to single circuit; just as with Legacy–Maentwrog, the arrangement uses only the top and middle crossarms, with the earthwire on one of the top crossarms instead of at the tower peak. Parts of the line have since been diverted, demolished or replaced.
The age of the line is not clear. Consultation of two Ordnance Survey maps puts the construction between 1938 and 1949, but Tom Gloag notes that “many of these lines weren’t mapped by OS at the time”. The maps in question are:
- “Revision of 1913 with additions in 1938”, on which the line does not appear
- “Revision of 1913 with additions in 1948–49”, which shows the Caergeiliog and Dolgarrog lines at Minffordd
The line is unlikely to be older than 1935 as the towers have the later high earthwire swing peaks introduced around that time, a marked deviation from the design of Eve’s other 33 and 66 kV tower types. Eve were still using the older-style peaks as late as 1936, with C333.
The Bangor to Caergeiliog line begins at Minffordd substation, south-east of Bangor (not to be confused with the village of Minffordd, Penrhyndeudraeth); this substation is also the terminus of the Dolgarrog–Bangor single-circuit 33 kV line. The latter line supplies power from Dolgarrog hydroelectric power station, which raises the question of how a single-circuit line could supply both Bangor plus a double-circuit line to Anglesey. However, the conductor types of both lines remain to be determined. Bangor already had its own generating capacity by that time.
General data
| Design contractor | J L Eve (unconfirmed) |
|---|---|
| Found | |
| Status | Historic, in service |
| Height (straight line tower) | ? |
| Voltage | 33 kV |
| Dates back to | Before 1949 |
| Known conductors | ? |
| Design conductor | ? |
| Design earthwire | ? |
| Circuit count | Double |
Progress
| Diagram coverage | None |
|---|---|
| Diagram source | None |
| Drawings needed | All |
| Photo coverage | Out of range |
| Information needed |
|
Lines
The known lines are:
- Minffordd substation, Bangor (Gywnedd), to Caergeiliog (Anglesey/Ynys Môn)
A short section of the line remained between Minffordd substation and another substation on the edge of Bangor (with the Bangor end replaced with wood poles). This line was replaced by wood poles sometime between 2015 and 2021, as shown by Google Street View, leaving just the terminal tower.
At some point prior to 1963 (the date on the Ordnance Survey map), Bangor substation was constructed adjacent to (the now closed) Treborth railway station. From the Minffordd end, the 33 kV line was diverted into the substation (away from new lines that no longer exist), seemingly on wood poles, and commenced anew towards Caergeiliog on the far side.
The 33 kV connection between Gywnedd and Anglesey now appears to be a 25 kV DC connection within the Britannia bridge, with 33 kV on Anglesey commencing from Llanfair PG substation.
Further diversions of the line on Anglesey—also on wood poles—run to Bodffordd and to Llangefni.
Tower forms
No material.
Tower details
No data.
See also
- Suspension tower, Bryn Ellyll (Geograph® Britain and Ireland)
- Tension tower, near Llangristiolus (Geograph® Britain and Ireland); note the strong similarity to other Eve types
- Terminal tower, Minffordd (Geograph® Britain and Ireland)