If you have any questions please post them here
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Hard to say leh.. Sometimes come two bus no.154 together.. Sometimes 15mins.. So agaration shld be not more than 15mins wait?Originally posted by iveco:I have waited more than 15 minutes for 154. -
i have waited about 25 min for 154 during sch holidays in the afternoon (just missed 9888Y somemore!)Originally posted by iveco:I have waited more than 15 minutes for 154. -
SBS2888T has a plug door, strange thing though, our SBST & SMRT plug doors open out v v wide in a swinging arc manner, unlike UK's doors wic slide out to the side for their articulated buses.Originally posted by tranquilice:Prototype bus excludes 1688K, it doesn't have exit plug door. Not sure about 2888T cause didn't took before.
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Thanks TamagoOriginally posted by ^tamago^:majority scrapped, but 10 buses were sold to Australia.
wat a waste...
btw any SMRT staff out there in this bus forum, pls note tt u have a Nissan bus hibernating at Geylang Lorong 1 Fringe CP for a long time, utilise it & let it start earning revenue... -
That is CSS294, and it is due for scrapping anytime soon.Originally posted by Acx1688:Thanks Tamago wat a waste...
btw any SMRT staff out there in this bus forum, pls note tt u have a Nissan bus hibernating at Geylang Lorong 1 Fringe CP for a long time, utilise it & let it start earning revenue... -
Where does the boost on MB0405s come from? There is a surge aft they move.Originally posted by ^tamago^:i'm very sure the MB O.405's uses a non-turbocharged OM447hA engine (SBST uses the older OM447h), while the O.405G's uses a turbocharged OM447hLA engine. note the L means turbo-charged.
LO3x's and VO3x's all have them. note the boost comes in only after a while after the LO3x starts moving.
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dunno. i jus noe they use 250bhp 12-litre engines, which is actually more powerful than a VO3x.Originally posted by SBS1908B:Where does the boost on MB0405s come from? There is a surge aft they move. -
The OM447h has a maximum output of 220 bhp@2200 rpm. On the other hand, the TD102KF develops 245 bhp. The Volvo engine has a higher power rating BUT the Mercedes has a lot of low-end torque. In other words, the maximum torque of the O405 occurs at a lower rpm than the VO3x. Plus, the O405 has a hub-reduction rear axle which helps in getting more torque to the wheels.
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Ah, I see......Originally posted by The_Bus_Guide:The OM447h has a maximum output of 220 bhp@2200 rpm. On the other hand, the TD102KF develops 245 bhp. The Volvo engine has a higher power rating BUT the Mercedes has a lot of low-end torque. In other words, the maximum torque of the O405 occurs at a lower rpm than the VO3x. Plus, the O405 has a hub-reduction rear axle which helps in getting more torque to the wheels. -
"Seniors", it's mentioned that a passenger bus is made up of engine chassis, body, and interiors (ie, seats). Pls enlighten on the selection process, as previously, MB0405s' & Volvo MKIIs' appeared in different bodyworks ....
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No Iveco, i mean a Nissan Bus in TIBS livery STILL hibernating in the CP. In addition, there's always another TIBS liveried Nissan bus parking at the extreme end together with other TIBS svcs. Shouldn the bus be on revenue svc? STRANGE SMRT & the fact is that there are insufficient buses for sme SMRT svcs...Originally posted by iveco:That is CSS294, and it is due for scrapping anytime soon. -
Pardon me for asking so many questions, but what is hub-reduction axle?Originally posted by The_Bus_Guide:The OM447h has a maximum output of 220 bhp@2200 rpm. On the other hand, the TD102KF develops 245 bhp. The Volvo engine has a higher power rating BUT the Mercedes has a lot of low-end torque. In other words, the maximum torque of the O405 occurs at a lower rpm than the VO3x. Plus, the O405 has a hub-reduction rear axle which helps in getting more torque to the wheels.
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If you look at the rear axle of a Mercedes O405 or a MAN 16.240, you will find a big cylinder in the middle. Inside the cylinder, there is a planetary gear system. This system is called hub-reduction. It further reduces the revolution of the final drive; hence increasing torque. The next time you ride an O405, listen carefully and you will be able to hear the hub-reduction in action!
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Now I know why these 2 types of buses have such a unique rear axle pattern. It is not just the 16.240 that has it, but also the 18.280. Merc OH series don't have such a feature, though.Originally posted by The_Bus_Guide:If you look at the rear axle of a Mercedes O405 or a MAN 16.240, you will find a big cylinder in the middle. Inside the cylinder, there is a planetary gear system. This system is called hub-reduction. It further reduces the revolution of the final drive; hence increasing torque. -
In Malaysia, I've seen the occasional OH1318 with hub-reduction! No kidding! Of course, the original axle must've been damaged.Originally posted by iveco:Now I know why these 2 types of buses have such a unique rear axle pattern. It is not just the 16.240 that has it, but also the 18.280. Merc OH series don't have such a feature, though. -
Anyone knows the url for the sg bus forum besides this one?
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no one knows the forum?Originally posted by PJ_Quek:Anyone knows the url for the sg bus forum besides this one? -
ask u ah...buses got how many gears?
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4 gears i guessOriginally posted by bismarck:ask u ah...buses got how many gears? -
My guesses.Originally posted by Volvo Olympian:4 gears i guess
SBST
MB0405 3
mkII 3
mkIII 3
mkIV 3
VO2X 3
VO3X 4
LO3X 4
VSO 3
Trident 3
CRB 3 -
there are mainly 2 makes of gearboxes for buses used in Singapore. One is from ZF, the other is from Voith. Both are German companies.Originally posted by bismarck:ask u ah...buses got how many gears?
ZF gearboxes used on our buses all have 4 gears. all but one of the buses using ZF uses the model 4HP500. Scania L94UB (SBS2888T) uses 4HP590 which is more suited for its 9-litre engine. ZF gearboxes feature a clutch lock-up at either the first or the second gear so dun mistake it as another gear (no 5 gears!). The advantage of ZF gearboxes is faster initial acceleration. Buses using ZF are:
- SMRTB Nissan UDs
- SMRTB O.405
- SMRTB Scania L113CRL
- SMRTB O.405G (some)
- SMRTB Hino HS3KRKK/HS3KRKA
- SMRTB Dennis Lance
- SBST Volvo B10M Mk-II
- SBST Volvo B10M Mk-IV DM (most)
- SBST Volvo B10M Mk-IV Strider
- SBST Volvo B10MA Mk-IV
- SBST Volvo B10M-70 Mk-IV 14.5m
- SBST Volvo B10BLE
- SBST Volvo B10BLE-CNG
- SBST O.405G
- SBST Scania L94UB
- SBST Leyland Olympian
- SBST Volvo Olympian 12m
Voith gearboxes used on our buses all have 3 gears (they do have 4-speed gearboxes but they are not used in Singapore and they merely have an extra overdrive gear tat kicks in at 70kph hence it is quite redundant). Models used on our buses are in the format xxx.3, where 3 actually denotes the number of gear speeds. The first gear actually has a dynamic gear ratio as it is totally hydraulical, while that of the second gear is ~1.36 and for third gear, it is 1.0. The advantage of Voith gearboxes is better performance with turbocharger-fitted engines since it holds the engine at higher rpms before shifting, and high rpms means the turbocharger turbine spins faster and becomes more powerful. Buses using Voith are:
- SMRTB DAF SB220LT
- SMRTB O.405G (some)
- SBST Volvo B10M Mk-III
- SBST Volvo B10M Mk-IV DM (few)
- SBST Volvo B10M Mk-IV DM3500
- SBST O.405 (few)
- SBST Scania N113CRB
- SBST Dennis Trident
- SBST Volvo Olympian 10.4m
- SBST Volvo Super Olympian B10TL -
There's different rated versions from the same engine model.
OM 447 h (fullly rated verson) is 250 BHP with earlier exhaust emission standard.
Lower rated version is 220 BHP, presumably for the smaller O 402.
OM 447 hLA can also be 250 BHP but with later exhaust standard like Euro 1.
OM 447 hLA (fully rated) 299 BHP which is usually used in the O 405 G instead.
Usually there's some 'trade-off' between power torque performance & the stringentness of the exhaust emission standard required, same engine you want higher performance then exhaust standard lower & vice-versa.
On paper i'll consider the Volvo's 245 BHP & the O 405's 250 BHP as marginal difference only. Therefore, other factors like choice of gearbox, gearbox & final drive gear ratios would utimately affect the performance in acceleration & road speed.
The O 405 being a citybus, is geared to have almost car-like acceleration up to approx. 74 km/h max. speed so as not to hold up car traffic on the busy roads in cities too much.
On the other hand there's supposely low end models like the OH 1318 with the OM 366 A only power 177 BHP yet these can be geared to attain max. road speed up to 130 km/h instead. Drawback of course is the snail or tortise-like acceleration like moving a heavy old train !! This model widely used in Malaysia by operators like Grassland, Sri Maju for mostly highway use. So you see, there's the 'trade-off' involved. Of course you want both acceleration & top speed to be high, can be done. Then go for the latest generation engines whereby they can output 400-500 BHP from just 12 liters capacity with Euro 3 exhaust standard like on the Travego coach.Originally posted by The_Bus_Guide:The OM447h has a maximum output of 220 bhp@2200 rpm. On the other hand, the TD102KF develops 245 bhp. The Volvo engine has a higher power rating BUT the Mercedes has a lot of low-end torque. In other words, the maximum torque of the O405 occurs at a lower rpm than the VO3x. Plus, the O405 has a hub-reduction rear axle which helps in getting more torque to the wheels. -
Correction.
The SBS M-B O 405 are naturally aspirated OM 447h you're correct to here.
The TIBS M-B O 405 & O 405 G & SBS O 405 G are all turbocharged with intercooling i.e. OM 447 hLA, where the 'A' means turbocharged, 'L' means with intercooler, 'h' means cylinders are horizontally opposed like boxer-style engine.
The Cummins engine used in (later) Leyland Olympians & Volvo & Scania engines tend to be turbocharged with intercooling.Originally posted by ^tamago^:i'm very sure the MB O.405's uses a non-turbocharged OM447hA engine (SBST uses the older OM447h), while the O.405G's uses a turbocharged OM447hLA engine. note the L means turbo-charged.
LO3x's and VO3x's all have them. note the boost comes in only after a while after the LO3x starts moving. -
Tibs' O405 uses OM447hA only, no 'L'.Originally posted by hseochin:Correction.
The SBS M-B O 405 are naturally aspirated OM 447h you're correct to here.
The TIBS M-B O 405 & O 405 G & SBS O 405 G are all turbocharged with intercooling i.e. OM 447 hLA, where the 'A' means turbocharged, 'L' means with intercooler, 'h' means cylinders are horizontally opposed like boxer-style engine.
The Cummins engine used in (later) Leyland Olympians & Volvo & Scania engines tend to be turbocharged with intercooling.
i thought 'L' means turbocharged, and 'A' is the first revision of the OM447h engine (like some sort of a mark II)?
and shldn't all turbochargers come with intercooler? without the intercooler there's really no point installing a turbocharger in the first place. the intercooler's function is to cool the hot & compressed (by the turbocharger) air taken in so as to attain a higher thermal efficiency. -
the surge is thanks to the gearbox. also, it has a higher-than-average torque at all rpm ranges so it has more torque to move forward at low speeds.Originally posted by SBS1908B:Where does the boost on MB0405s come from? There is a surge aft they move.