HTM GTL8 tram

[RotterdamMetroLover]

Your 1st guess is wrong, this tram only runs at 600V. 2nd guess is correct, the rear panto is used when the front panto is damaged or sometimes the drivers just use the rear one instead of the front one.

[Sjoerd]

And I was wondering, what are Michiel and Sjoerd up to with Metrosim, so there's almost no activity in this forum. I guess this answers my question.

We still have plans, and are working on new projects. Just remember it is still just a hobby, so developments may not be as fast all the time...

But I now wonder, Why does GTL8 tram has a pair of pantos, when it's unidirectional?
My guesses, why is that, are:
1st: Different panto is used in different situations. For example: if the tram is street-running on runs on normal tracks, it has the front panto lifted up, and if the tram is on the tram-expressway or on high speed track, it has it's rear panto lifted up.
2nd: The rear panto is the backup one. If the front panto gets damaged or destroyed, the rear panto is lifted up, allowing driver to get the crippled tram to the depot for fixing.

I think the reason is actually more historical. The GTL8 trams where designed to be the next generation trams, intended to replace the sets of two coupled PCC trams (two coupled standard motorcars, or a motorcar with a motorized trailercar, like the 1300+2100 combination: https://busposities.nl/tn/9d/e0/b2/8596 ... 43fec5.jpg). With such trams, you have two motorcars coupled together, hence two traction installations, each with their own pantograph.
When the GTL trams here built, they where technically build with two traction installations; one for the front two bogies, and one for the rear two bogies (there is a selector switch at the driver position to activate only one, or both together).
I guess they thought it would be reasonable to mount two pantographs too, even though one is enough to get enough power to 'feed' both traction installations.

In practice, only one pantograph is used, most often the front one. But there has been a year where the HTM decided all trams should use the rear one as the default pantograph; as a way to have them wear down more equally (change back to the front one als de default one after one year, and so on).
But this was not really repeated after that; before the year using the front one again was up, they decided to remove the back one, store them, and use those as spare parts. Until later, the front ones where replaced by a newer model (the same type as the Regiocitadis pantographs).

The second pantograph (aside from which one was 'the second' at that moment), when they stil had it, was mostly used as a backup. If the primary had a defect, or a worn out top surface, there was no need to go to the workshop immediately; the vehicle could still go into service using the other pantograph until the next scheduled regular maintenance.

At the moment, only the vehicles refitted to be "Pekeltram" (https://hovm.nl/kijk-deel-3-van-40-jaar ... pekeltram/) have their two (original) pantographs intact, and when doing their duty, regularly use both of them. As these trams are doing their intended purpose (keep the tracks snow/ice free with a salt solution; "Pekel". There are large tanks for this in the former passenger area), they also make sure the overhead wire stays ice-free by scraping off any ice by putting up both pantographs; when there is ice on the overhead wires, the front one will scrape it off (at the cost of less efficient electrical contact), while the back one ensures the electrical contact, thereby avoiding electrical sparks while driving.

[Sjoerd]

Created the variant GTL8-II, series 3101-3147, which were delivered in a blue-white livery with yellow doors. Main differences: Doors open swinging out (like on Dutch Railways trains), larger destination display front and side.

[brozma]

Your 1st guess is wrong, this tram only runs at 600V. 2nd guess is correct, the rear panto is used when the front panto is damaged or sometimes the drivers just use the rear one instead of the front one.

Oh I see. I guess, the spare panto may come in handy sometimes.

Also that 1st guess, was derived from, how Prague transport company operated Tatra KT8D5 trams back in 2003 - 2004, when the tram-expressway between Hlubočepy and Barrandov districts was first opened. When Tatra KT8D5 entered the tram-expressway and stopped at Hlubočepy station, (the station at the start of the said tram-expressway), the driver swapped the the pantos around (from front panto to rear panto), the same procedure was repeated, but in the opposite way (from rear panto to front panto), when the Tatra KT8D5 was leaving the tram-expressway. This was done, because Prague transport company was concerned, that the contact wire in the catenary may start "jumping/wiggling,[1]" if the front panto was used on Tatra KT8D5 at high speeds on tram-expressway. This was only done in the first 2 months after opening the already mentioned tram-expressway. After that the procedure with swapping the pantos was dropped entirely.


Footnotes:
[1]: If the contact wire starts "jumping" or "wiggling," it means, that the contact wire on the catenary started wiggling too much. This is usually caused either by panto-mounted vehicle moving too fast on the section with inappropriate wire suspension, or by panto-mounted vehicle, using incorrectly placed panto. This is also the reason, why the electric locos usually uses their rear panto, when running, because using the rear panto highly reduces the proabability, that the contact wire starts "jumping/wiggling." If the contact wire is "jumping/wiggling too much", this can either cause a bad contact between the contact wire and the panto's collector slider, leading to arcs, or in extreme cases, the contact wire can detach itself from it's suspension.

[Nextor162]

Created the variant GTL8-II, series 3101-3147, which were delivered in a blue-white livery with yellow doors. Main differences: Doors open swinging out (like on Dutch Railways trains), larger destination display front and side.

Will the new version also come? with larger bumper at the front?

[RotterdamMetroLover]

I don't know about that yet. The 'old' front (still hiding under the new one, as seen here: https://haagsetrams.com/gtl/midlife-rev ... erie-3100/) definately looked a lot better. And I do not really plan to make every single variation of this tram (but at least the red-beige livery, the white-blue livery, and probably a repaintable one).

[Sjoerd]

Now with more correct pantographs;

[brozma]

Those pantos look like diamond-shaped pantos used by Tatra trams, only they're black, not yellow nor orange. But looking at the real picture in the 1st post, I think they're accurate

[Sjoerd]

I decided to do the most current state of this tram too... Today I created the new "collision friendly" front of the tram. This version also reqiures more modifications (like the doors and digital destination displays); those come later. This screenshot is a test of the new front.

(Example: https://nl.wikipedia.org/wiki/Gelede_Tr ... n.2013.JPG)

[Sjoerd]

GTL8-II, current variant (example: https://haagstramnieuws.org/gtl/2018-09.jpg):