STL1

STL1 is a North of Scotland Hydro-Electric Board (NoSHEB) specification for 132 kV towers. No details are known. The specification is cited on some (but not all) general arrangement and erection diagrams for the following types:

• Blaw Knox K9857; this appears to be a duplicate of PL16 but with redesigned line towers (D2 and DD2), that would become PL16 D2S and DD2S
• Blaw Knox K1201 (single circuit equivalent to the SWE PL16 towers)
• Blaw Knox K1420 (flat formation, angle towers only)

The relationship with and any major differences between STL1 and CEB L132 are not known.