ABQ RIDE Posted May 30, 2012 Report Share Posted May 30, 2012 I was wondering, does anyone know what are the advantages and disadvantages of using roof-mounted vs. rear-mounted LNG tanks? New Flyer uses roof-mounted while NABI and ElDorado use rear-mounted. Which has me also wondering, if Gillig wins the City of Phoenix contract (which includes diesel and LNG buses), will Gillig use roof-mounted or rear-mounted LNG tanks? If I would guess, they would use roof-mounted, since rear-mounted tanks would require a rooftop HVAC which Gillig doesn't seem to like. Link to comment Share on other sites More sharing options...
306 Carlton Posted May 30, 2012 Report Share Posted May 30, 2012 Link to comment Share on other sites More sharing options...
Ramirez Posted May 30, 2012 Report Share Posted May 30, 2012 I'd say rear mounted, less height for the bus and it gives more clearance from low lying structures And nobody gives a damn about the ponies Link to comment Share on other sites More sharing options...
306 Carlton Posted May 30, 2012 Report Share Posted May 30, 2012 I'd like to see some pictures of these rear mounted CNG tank buses. Link to comment Share on other sites More sharing options...
Ramirez Posted May 30, 2012 Report Share Posted May 30, 2012 OCTA NABI 40LFW LNG (Rear Mounted) http://farm5.staticflickr.com/4149/5046754994_6b4f555df8_z.jpg Santa Monica NFI L40LF (Roof Mounted) http://farm8.staticflickr.com/7161/6577930073_212f7a89dd_z.jpg I'd like to see some pictures of these rear mounted CNG tank buses. You meant LNG tanks, right? Link to comment Share on other sites More sharing options...
306 Carlton Posted May 30, 2012 Report Share Posted May 30, 2012 OCTA NABI 40LFW LNG (Rear Mounted) http://farm5.staticf...b4f555df8_z.jpg Santa Monica NFI L40LF (Roof Mounted) http://farm8.staticf...12f7a89dd_z.jpg You meant LNG tanks, right? Yeah thats the one. I also want interior pics please and thank you. I can only imagine that roof mounted would be more accessible for maintenance, let alone its farther away from the main heat source, aka the engine. The bus would likely be more balanced with it centered on the roof anyways. This is just like, my opinion though. Not like I know much about anything mechanical anyways. Link to comment Share on other sites More sharing options...
ABQ RIDE Posted May 31, 2012 Author Report Share Posted May 31, 2012 The Valley Metro (Phoenix and Tempe divisions) NABI 35-LFW and 40-LFW LNGs also have rear-mounted LNG tanks, except they don't have that hump over the back like the OCTA buses. Link to comment Share on other sites More sharing options...
306 Carlton Posted May 31, 2012 Report Share Posted May 31, 2012 The Valley Metro (Phoenix and Tempe divisions) NABI 35-LFW and 40-LFW LNGs also have rear-mounted LNG tanks, except they don't have that hump over the back like the OCTA buses. Where does the tank go then? It must be small! Link to comment Share on other sites More sharing options...
ABQ RIDE Posted May 31, 2012 Author Report Share Posted May 31, 2012 Where does the tank go then? It must be small! It's in the cavity where the HVAC or rear window would normally be located as far as I know: Link to comment Share on other sites More sharing options...
Ramirez Posted May 31, 2012 Report Share Posted May 31, 2012 Yeah thats the one. I also want interior pics please and thank you. I can only imagine that roof mounted would be more accessible for maintenance, let alone its farther away from the main heat source, aka the engine. The bus would likely be more balanced with it centered on the roof anyways. This is just like, my opinion though. Not like I know much about anything mechanical anyways. There's not much diffrence inside for both, except the NABI has a plain wall at the back where the HVAC is supposed to be at (Unless you're willing to see a Los Angeles CNG version of the NABI interior, http://farm9.staticflickr.com/8146/7168582942_d9132ffcef_z.jpg) What I do know is that OCTA & Santa Monica NABI's (they have them too http://farm7.staticflickr.com/6084/6055862803_bddb8fd2c0_z.jpg) is that they are having problems with them (idk about Valley Metro) although I have no idea what the problems are Link to comment Share on other sites More sharing options...
306 Carlton Posted May 31, 2012 Report Share Posted May 31, 2012 How can you know for sure? Or are you assuming? Link to comment Share on other sites More sharing options...
Ramirez Posted May 31, 2012 Report Share Posted May 31, 2012 How can you know for sure? Or are you assuming? LNG doesn't take up that much space, think of it like Diesel Link to comment Share on other sites More sharing options...
306 Carlton Posted May 31, 2012 Report Share Posted May 31, 2012 LNG doesn't take up that much space, think of it like Diesel Yes but LNG has a lower calorific value than that of diesel. Say in theory one bus has a 100 Gallon tank of diesel and another has a 100 Gallon tank of LNG. The diesel bus will go much further on that same volume of fuel. If the LNG bus has a smaller tank than that of a diesel it must be a fairly low range vehicle... having a roof mounted tank gives all that much more than having a teeny tiny tank in that small space above the engine. Logistically, I find LNG far inferior to that of diesel, but for the sake of the topic the roof mounted tanks are a better design. Link to comment Share on other sites More sharing options...
ABQ RIDE Posted May 31, 2012 Author Report Share Posted May 31, 2012 Also, another difference between the Valley Metro and OCTA/Big Blue Bus NABI LNGs is that the Valley Metro buses have Cummins C8.3G/C Gas Plus engines, vs. Detroit Diesel Series 50G engines on the OCTA and Big Blue Bus NABI LNGs. The DD 50G is a slightly larger engine than the Cummins C8.3G/C Gas Plus. Link to comment Share on other sites More sharing options...
306 Carlton Posted May 31, 2012 Report Share Posted May 31, 2012 (edited) Also, another difference between the Valley Metro and OCTA/Big Blue Bus NABI LNGs is that the Valley Metro buses have Cummins C8.3G/C Gas Plus engines, vs. Detroit Diesel Series 50G engines on the OCTA and Big Blue Bus NABI LNGs. The DD 50G is a slightly larger engine than the Cummins C8.3G/C Gas Plus. 0.2L displacement difference will not really make any sort of difference... Let alone that S50G will be working harder anyways. EDIT: I think you may have been refering to the physical dimensions then yes the S50G is a taller engine. Edited May 31, 2012 by 306 Carlton Link to comment Share on other sites More sharing options...
Ramirez Posted May 31, 2012 Report Share Posted May 31, 2012 EDIT: I think you may have been refering to the physical dimensions then yes the S50G is a taller engine. That's the reason why the OCTA/SM NABI's has those bumps + they have to fit that cooling system because the tanks are near the engine That's what a ex-OCTA operator told me Link to comment Share on other sites More sharing options...
ABQ RIDE Posted May 31, 2012 Author Report Share Posted May 31, 2012 And actually, the OCTA NABI LFW LNGs have been repowered with Cummins ISL G engines. But yes, they originally had Detroit Diesel Series 50G engines, except 2102 which had a John Deere 6081 engine and 2259 which had a Cummins C Gas Plus. Link to comment Share on other sites More sharing options...
306 Carlton Posted May 31, 2012 Report Share Posted May 31, 2012 Link to comment Share on other sites More sharing options...
Ramirez Posted May 31, 2012 Report Share Posted May 31, 2012 :meme: :Poker Face: The best I can do Link to comment Share on other sites More sharing options...
Bus_Medic Posted May 31, 2012 Report Share Posted May 31, 2012 Boston? Link to comment Share on other sites More sharing options...
general682002 Posted May 31, 2012 Report Share Posted May 31, 2012 Boston? Was trying to figure it out who's yellow painted lines are, that would be it! Link to comment Share on other sites More sharing options...
smallspy Posted May 31, 2012 Report Share Posted May 31, 2012 Boston? Looks to be. I see nothing that resembles any sort of fuel storage back there either... Dan Link to comment Share on other sites More sharing options...
Ramirez Posted May 31, 2012 Report Share Posted May 31, 2012 Looks to be. I see nothing that resembles any sort of fuel storage back there either... Dan I apoloigize for that, I put up the wrong fuel type (that picture is a MBTA NABI 40LFW CNG, not LNG) I have asked a friend if he could provide me a photo of the correct bus Link to comment Share on other sites More sharing options...
Recommended Posts
Please sign in to comment
You will be able to leave a comment after signing in
Sign In Now