Driving a 40 ft School Bus / Day 1

Driving a 40 ft School Bus / Day 1

I spooked my otherwise good driver trainer Samantha by going faster around corners & a hint above the speed limit on longer curvy hilly straights up & down hills on the way back to the School Bus garage//

Learning left & right turns & keeping the bus lane centered was a constant fast thinking sight line mirror cycle checking challenge. Joe Lee our other driver trainer & someone who I look up to as a mentor did a great job with the demo drive actively declaring what he was doing while driving to help prime John & I for our first drive in the Renton Highlands, Washington State, USA.

Buss Performance Impressions

Sluggish to accelerate & speeds up easily down hills, modulating the low speeds with the brake pedal was really a matter of lifting off of it to go slow, which I found challenging & ended up going too fast around corners. The specific performance unsurprising given the 33,000 lb mass of the 40 ft 15 row passenger School Bus. 

Brake & Gas Pedals & Steering

Very touchy or sensitive air brakes that are extremely different than those hydrolytic units on our 2005 Toyota Prius daily driver or Yamaha MT-03 motorcycle or our PCX Scooter or 2010 Prius or 2001 Audi A4 Quattro. Short travel with fast progression of input to brake activation, they are very effective at slowing the bus, quickly if you apply them harder. A very sensitive brake pedal input, thankfully you can adjust the petals forwards or backwards with push button controls :) A newer driver, greenhorn or newbie will likely find the brake pedal sensitive or challenging to modulate smoothly, giving passengers a forward backward rocking experience as the brakes grab hard easily sending them forward in their seats easily. 

The gas pedal kind of sluggish or slow to respond & requires that you press it down more to actually get the bus going. I would describe this as a kind of numb input. Brisk acceleration requires deep pedal input & the difference between brisk & full blast are close, so a narrow end of the pedal throw range where articulation of the throttle makes the most difference, towards the pedals end of travel position as you depress the pedal with your right foot.

The steering wheel input responsiviely quick but also relatively light given the size & mass of the Bus. I would describe it as very connected or direct feeling, like a sports car without power steering, but lighter & easy to articulate the front steering wheels at at a stop orphan driving low speeds. A very powerful power steering pump unit produces the strong power steering assist. 

Use Configurable Driver IO Thankfully

 

Thankfully the pedals are fully adjustable, as is the steering column & driver seat, a nice squishy spring of shock absorbed loaded unit that slides forward & backward with lumbar support & adjustable back. The steering column is tilt & telescopic adjustable. The buttons & switches of which there are many are water resistant too since the bus has to be operated with the windows open due to COVID19 ventilation requirements. 

Many Mirrors Awesome 

Wow are they useful, with many different near & wide angle units to give tons of ways to view the busses lane position actively while driving & while positioning it at low speed. A radical divergence from the typical 3 mirror of a car or two mirror of a motorcycle, the bus has 6 outside mirrors that you align before driving. A seventh passenger mirror inside enables you to see the passengers & out the back window to tell if someone there, like a car or person, since the bus has a huge rear blind spot. 

Acceleration

On the one hand the cummins turbo diesel delivers a ton of torque & accelerates the Bus ok from 0-25 mph, but hills really slow it down & make it work harder. Thankfully the busses are equipped with VGT which enables the engine to engine brake when the bus going down hills & there are a lot of hills in the locals nearby. 

Late Turn 2 pt Sight Aligned Initiation 

Overall Idea ; Pull forward straight past the turn, the front wheels are 5 feet behind you, then when you reach a sight point alignment, turn the wheel 100% in the direction of travel to complete the turn while enabling the dually tires 34 ft behind you to clear the curb or traffic parked in the oncoming lane by about 1 ft as you complete the turn & correctly recenter the bus into the lane of travel. 

Right turn sight line turning involves pulling the bus straight forward into a turn then aligning a lane feature of the lane your turning into with some part of the doorway with glass windows that allow your eyes to see when the sight line point, like a fog line, lines up with a vertical line in the door window edge when you then 100% turn the wheel all the way. This must be done so that the dually wheels 34 ft behind you that are trailing will clear the curb edge of the turn & not hit the curb. This involves getting the bus completely into the oncoming lane, then returning to the lane of travel by steering right & then left to straighten out the bus back into the lane. 

Left turns are similar where you pick an alignment sight line near your shoulder or forward in the drivers window & initiate a turn when that point alines with the double yellow lane line in the lane you are turning left into. Timing the turning & entering comes down to your approach speed, when you initialize the turn & when you straighten out & use small steering corrections later in the turn so that your dually wheels do not clip a car in the oncoming lane of the roadway you just turned into. Coordinating the timing visually & kinesthetically not easy & requires skill refinement.

Fun Challenge To Drive A Bus Well

Room for constant improvement, the School Bus driver could spend a lifetime getting better at precisely articulating a bus with excellent repeatable accuracy, low to no errors & excellence while driving. It’s like a moving goal, there is always room for improvement. I have a lot more respect for bus & truck drivers now, not just for passing all the tests to become one, but also the level of driving skill required to drive large commercial vehicles well! 

Parking Brake Important

Like your underwear, first on & last off, said Violeta during our reverse backup serpentine driving yesterday in a cone lined parking lot between Issaquah Middle & High School, where the buses drop off & pickup students. The parking brake input a push to release, pull to apply unit with a diamond shaped yellow handle to the right of the steering wheel. You grasp it with your hand & pull to apply the parking brakes or push it down with your palm to release the parking brakes. 

Noise

Its loud, you can hear the wind, road noises from the tires & the turbo Diesel engine roaring away in the back of the bus. Turbulent airflow around the numbers front mirror & stop paddle & the flat shape of the front of the bus creates a lot of wind sounds, like air rushing, high pitch hissing sounds at high enough decibel levels to cause hearing damage, especially bad because COVID19 operating restrictions require all the windows to stay open while the bus  operating. 

The windscreen fans are so loud there is a silence button to turn them & the radios & other noise making features of the bus turn off all together as bus drivers are required to listen at train track crossing, as looking alone not enough to detect a train 14-15 seconds away, especially if the track is curved out of view or a landscaping feature creates a visual blind spot inhibiting the drivers from looking down the tracks a safe distance so as to avoid a potential train bus collision when crossing train tracks with a bus full of children that other people have entrusted the driver to protect as much as possible! 

The air tank drain valve expels air through a small tight nozzle that produces a very loud rushing air hiss sound as you do the pre-trip inspection & actuate this valve to purge any possible water or oil that may have condensed to the bottom most point in the air tank system. This is very important that no water or oil be in the air brake line as they can create a freeze plug that would disable braking function of the service brakes when the bus operating in freezing winter conditions, especially while its parked overnight where temperatures outside often get to the lowest levels. 

Vibration 

While the total mass of the bus & leaf spring suspension with shock absorbs helps to dampen vibration, you can feel the transmission shifting & the VGT system activation when going down a hill as it uses resistance in the engine like downshifting in a manual to help slow the buses rate of travel when descending hills. Much of the mechanical energy translated to the passengers a function of rates of deceleration with the brakes, speed around corners & undulation caused by uneven roadway conditions between the front & rear axels that tilt or rock the bus as it travels forward. Thankfully the drivers seat contains dampening to limit driver fatigue NVH or noise vibration & harshness from the very strong ridged travel. 

Harshness 

The buss a massive metal latter body on frame assembly with lots of heavy steel & iron contributing to the 33,000lb mass of the buss. 100 gallons of diesel & all the other oils & fluids add even more mass. When the bus full of children & their instruments, backpacks full of books & other gear, the gross traveling mass of the bus increases further. This means the bus a very stiff vehicle with very little body flex, so perturbations like pot holes in the roadway can be easily felt by driver & passenger, like a tuning fork being struck by a hard object, the frame does not bend easily but rather harmonically oscillates at a specific range of dynamic frequencies. The bus right not as rough or harsh as a driving a lowered sports car, but more like operating a fire truck or concrete truck, or other large long wheel base heavy vehicle.

Body Roll

With a very high center of gravity when loaded, going around corners faster than 10 mph dangerous. The driver instructors working with new bus drivers encourage going 3-5 mph around corners at first because you have to check mirror 5 to see that your read dually wheels cleared the curb or ditch drop off by 6-18 inches, aiming for about 12 inches as ideal. The bus has a propensity to tip or roll in corners, very much unlike a lowered sport car & more like other SUV's with a higher center of gravity & softer suspension. Slower & smoother driving required to skillfully operate the bus safely. 

Cool or Cold & Wet

While the bus has a heat pump & heaters & defrosters, having to keep the windows open 24/7 means the inside of the bus gets very cool or cold by the early morning hours after overnight temperature drops have taken away heat from the bus & its engine & transmission. On cold startups in the morning you have to turn the bus on for 10-15 seconds for the glow plug heaters to warm up & for all the systems on the bus to start before cranking over the turbodiesel engine. All the gauges, of which there are many, indicate the oil pressure increasing rapidly on startup, the water temperature gradually increasing to near boiling temps once fully warmed, the air pressure in both tanks of the air brake system. PVT pressure volume temperature relationship means the air tank fill rate depends on the ambient air temperature as does it total volume. 

I will need to obtain a waterproof Goretex or similar winter jacket to operate the bus during the cooler winter weather with all the windows down due to covid19 venting requirements. I can imagine the bus will become very cold, including the drivers seat. Also the pre-trip inspection requires going outside the bus & in cold rain that could be a real bummer without adequate personal warming clothing gear thats water resistant & breathable.