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<p>Great idea. Not sure about using "3rd" and "4th" though - it's a bit tightly coupled to the English language and possibly prone to error. Wouldn't "3rail" and "4rail" fit the bill?</p>
<p>Actually, as electrified=rail is so widely used at present, how about making that explicitly "3rd rail" and introducing a new value for the 4-rail system?</p>
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<p>How would we indicate the voltage/frequency of the two rails independently? On the London Underground it's mostly +420/-210 (these days +500/-250) but there are some areas where +750/0 is used (Richmond-Gunnersbury for example).</p>
<p>While we are at it, could we take the opportunity to find a way to represent three-phase dual-overhead systems (Switzerland etc) as well?</p>
<p>Colin</p>
<p>On 2020-06-09 10:13, Garry Keenor wrote:</p>
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<div dir="ltr"><a href="https://wiki.openstreetmap.org/wiki/Proposed_features/3rd_and_4th_rail" target="_blank" rel="noopener noreferrer">https://wiki.openstreetmap.org/wiki/Proposed_features/3rd_and_4th_rail</a>
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<div>Definition: A track electrified with a 4th rail system, with two additional rails on insulators and two shoe pickup by the train, and traction current returning via one of the insulated rails </div>
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<div>best regards,
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<div>Garry</div>
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