Southern Coach

[mmanning]

Just ran across this video on YouTube:  https://youtu.be/A6y864LlmKA

I realize I'm new to bus conventions, but I have never seen a bus with the engine on the bottom.  I also really like the layout of this bus.

[Iceni John]

That's a beauty.   Fageol-powered RVs and conversions aren't common!   However, mid-engine buses really aren't that rare  -  Crown (obviously), Gillig, ACF Brill and maybe some others in this country, and many other makes in Europe and elsewhere.   Mid-engine buses handle well, but finding underfloor spaces for tanks and whatnots is always a challenge when converting them.

John 

[Jeremy]

My bus is mid-engineed 

Jeremy

[mmanning]

I had no idea mid engines were a thing, let alone somewhat common.  Is there a benefit to the mid engines compared to the back of front?

[chessie4905]

There is a reason that all coaches are rear engined now. Efficiency in design and space utilization.

[Jeremy]

Pretty sure there are still plenty of mid-engineed buses and coaches around if you look. Why wouldn't there be? The arguments favouring rear layouts in some applications and mid layouts in others have never changed. In fact with the growth of hybrid and electric buses I'd expect a mid-layout to become more popular, not less

Jeremy

[chessie4905]

Mid layout? Electric motors obviously would be at the wheels, front or  most likely rear. Batteries would be in mid section. Completely different application than what we are talking about.

[Jeremy]

In fact very few electric vehicles have their motors at the wheels - even with 100% battery-powered vehicles (and with the exception of the low-speed 'shopper' type of vehicle) there is almost always some form of transmission between the motor and the axle, and in the case of buses most are hybrids and have powertrains which are really quite complicated

In the case of traditional diesel buses, mine (as an example) was what was called an 'Armchair' version of the Plaxton Paramount, meaning it was designed to have fewer but larger & more comfortable seats than a regular coach, plus an over-sized (6 foot tall) rear baggage which you can (almost) walk around in and which extends up into the normal passenger compartment at the back of the vehicle - which you clearly couldn't do with a rear engine layout. As I say, rear layouts suit some applications, mid layouts suit others

Jeremy

PS - I've built a slide-out into my rear bay, but this is another Plaxton Paramount which has made a different use of it:

[chessie4905]

Rear layouts serve MOST applications. Mid drive are niche players.

[Jim Blackwood]

Not too common over here.

Jim

[buswarrior]

The challenge with mid-engine is fitting the engine in the space under the floor.

Cummins and Detroit had engines which could lie on their sides, an old Hall Scott engine ran the cylinders horizontally too.

Nobody making a lay down engine today?

Working on the mid engines was challenging, with the bus floor constantly in the way.

Engine noise, engine change out, front axle loading once the customers join in...

However, Van Hool has a current articulated bus that has midship drives that I'd like to know more about.

Happy coaching!
Buswarrior

[Jeremy]

The engine in mine is completely conventional (a Bedford 500, which is a 500cu.in straight 6 with turbo) and just sits upright between the chassis rails. There is still a middle baggage bay on one side of the bus but the other side is left open to provide access to the engine (and the spare wheel etc, which is in that area). I've got the generator mounted there now as well

What is 'wasted space' on my bus is actually the area immediately in front of the engine (which contains the radiator and not much else), and the area behind the engine and above the rear axle. I'll be putting the water tanks in the rear area but that front area is pretty-much unusable without moving the radiator, which I don't plan to do

There is undoubtedly a bit more imagination involved when converting a mid-engine bus, but there is still room for everything, and when I'm finished I will end-up with that big rear baggage bay still completely empty

Jeremy

[CrabbyMilton]

Regardless of the engine placement, that is a true beauty.
However, the rear engine idea obviously won out for many reasons.

[buswarrior]

And accessibility requirements have driven the low floor design.

No space for anything between the cardboard sandwich flooring and the road...

MCI has a new low floor D model coach for sale now for commuter service.

All the manufacturers now seem to stick to the low floor in front to the mid body exit doors, then traditional high floor over the rear axle and rearward. The same three steps up found at the old doorway is inside the coach, just ahead of the differential. T-drive of your choice in the rear.

Happy coaching!
Buswarrior

[richard5933]

Doesn't the rear-engine layout make it easier to balance the weight on a two-axle bus? Without a bogie or tag axle, the only way to keep the front axle from being overweight is to shift a substantial counterbalance to behind the rear axle. I see lot's of 35 and 40 foot buses in the local area with only two axles, and I imagine that low-floor requirements aside the weight balance issue would be a problem with a mid-engine bus.