Reakcia na: Red-Hawko #55717:
"Aky je vlastne rozdiel medzi elektrickou a metrom? Hmm? Lebo mam pocit ze sa tu pletie 5te cez 9viate. h? Nieje to nahodou tak ze metro je podzemou (preto sa to vola asi 'underground') a elektricka na/nadzemou." - Nie metro v zásade nemusí mať ani meter trate pod zemou a naopak, električka môže viesť aj v tuneli. Dovolím si citovať definíciu metra z urbanrail.net, ktorá môže pomôcť tým, ktorí v tom nemajú jasno: What is a metro? A subway? An underground?
1) An urban electric mass rail transport system, i.e. it is primarily used to move within the city
2) Totally independent from other traffic, rail or street traffic
3) High frequency service (maximum interval approx. 10 minutes during normal daytime service)
Obviously a metro does not have to be underground (this is why I prefer this term to 'subway' or 'underground' or 'U-Bahn' as all these terms imply a tunnel), it can also be elevated or at grade. A metro does not necessarily use heavy rail technology, therefore the Docklands Light Railway or the Lille VAL are full metro services, with the only difference that their capacity is smaller according to the needs of the city/area they serve. It's also irrelevant whether the metro runs on steel wheels or rubber tyres, is monorail or conventional double rail, uses third rail power supply or overhead wire, is fully automated or has a driver, has standard, narrow or broad gauge.
There are many mixed forms nowadays and probably there will be even more in the future. In Europe (especially Germany and the Benelux) light rail systems (Stadtbahn, Premetro) have been bridging the gap between metros and trams for some decades now and provide, in most cases, a perfect service in their city. For the time being I can only cover these mixed systems (which I'd like to refer to as metroTrams) in Europe only, although also in America and Asia more and more networks of this kind are being built.
tr3mp
Re #55680 Red-Hawko: "Tunel musi byt aspon 20metrov pod dunajom a to neviem kde by to vyslo nad zem v 'Ba casti' niekde na Kammennom namesti?" - Keby sme mali tunel popod Dunaj, tak nie je potrebné riešiť, kde vyjsť v centre na povrch - pokračovalo by sa ďalej podzemne.
Ešte k téme mosta a tunela. Posledný tunel metra popod Vltavu v Prahe medzi stanicami Nádraží Holešovice - Ládví stál 5 447,0 mil. Kč, teda cca 7 mld. Sk. Ako sa uvádza na stránke zhotoviteľa tunelu spoločnosti Metrostav (http://www.metrostav.cz/cz/reference/referencni_stavba?id=200), "Realizovaná technologie je rychlejší a levnější, méně závislá na vnějších vlivech, ale technicky náročnější." - Čiže dlhší tunel popod Dunaj stavaný zrejme inou metódou by bol podľa môjho názoru drahší ako spomínaných 7 mld. Sk.
Len na porovnanie, v Prahe sú všetky štyri prechody popod rieky realizované tunelovo.
V Paríži je 6 prechodov mostom a 7 tunelom.
V Porte (čo by mohol byť podľa mňa vzorový systém pre Bratislavu) je jediný prechod cez rieku Douro mostom.
Čiže tunel aj most sú vhodné riešenia na prechod rieky, je len na miestnych podmienkach, ktoré sa vyberie.