Rain.
Yes, it does rain in the Seattle area. Rain poses a special set of complications for the operations of the train. You will recall my descriptions of the track run at woodland park, where the hills and slopes of the terrain are ever changing, with significant downgrade, transitions from down to up and back and a fair number of curves and turns thrown in.
Most times, the grades were routinely handles with the appropriate levels of throttle, brakes, or combinations of both. Sometimes, however the weather intrudes on that routine.
If the weather was bad, most days we'd just not bother bringing the train out of its tunnel/garage for the day as the customer loads just didn't justify the trouble. The train was the major attraction at the amusement park at the zoo and we avoided operating it on very light days. After all, off road (Non-Road Tax) gasoline was about 12-15 cents a gallon at the time, couldn't waste it.)
If the weather was on and off rainy, or if the showers arrived during an otherwise busy day at the park, we'd soldier on through the rain, as long as it didn't look like a steady storm. Again this choice was made strictly on business grounds. (As long as enough people bought tickets, around I went). We found that if the seats got all wet, folks would not be as interested to sit and go through the loop.
Back to operations. I've described the large, sweeping uphill grade turn at the far North end of the run. Elephant Barn Hill I've named it due to (surprise) the proximity to the elephant barns in the park. From the bridge over the path to Lower Woodland, the track was slightly downgrade, then changed to a short straight away of neutral grade then uphill around the curve we went. It's important to remember that any train, Regular Size, or Park sized, required more power on a level grade going around a curve then on a straight away. More often than not, this is not too noticeable on a fairly level track. Think of the drag the wheels have on the rail, when the train is being pulled around a curve. That's why a curve, even absent a hill, it takes more power to overcome that drag resistance.
Add the significant up grade with the curve, and you'll understand where in the run I really let out the horses of the V-4 Wisconsin's to pull my customer filled cars up hill and around the curves. I loved the sound of the G-16 doing it's stuff up that hill as they were working hard. A full train, just in people weight, could be north of 4,000 lbs.
Rain. It was a funny thing about rain, and wet rails and uphill grades. The effect of wet rail was something a bit different then what you might expect. If the rail was dry, well that was routine, and other then mis-judging when and how much power to apply, dry rail was not a problem. Even if I was late adding power, and lost momentum, I god lug up the last part of the fill at full throttle, even if the train was barely creeping. (Embarrasing !)
Counter-intutive, when the rail was COMPLETLY wet, then again, other then the rain in my face, the trip up the hill was pretty normal. Sure I had to be a bit more alert for wheel spin, and I had to feather the throttle a bit to maintain good rail to wheel contact, but it was not a huge problem.
But, if the day started dry, and then some light showers arrived in the middle of the work day, I had a problem. Seems that PARTIALLY wet rail, acted like wet ice to the small steel wheels of the MTC G-16 pulling the train weight up the hill.
I'd start powering early if I noticed sprinkles basically just after the bridge using the downhill, level section to grab a couple extra MPH's before I went up the big curve. But likely as not, if the rails were just partially wet, despite my best efforts to notice the first hint of rail slip and back down power and try to regain some tractive effort, I'd stall out somewhere up the grade as the wheels would just slip, and not create any pull at all. At that point, I had no choice. Without an operable reverse on the train (The Woodland Park units were always in forward), I had to shut down the engines, jump out, run up to the nose of the A Unit and pushed the train, and people, back as far as I could towards the bridge to get another run at the hill.
Often, and against my instructions, the 'helpful' customers would also jump out to lend a hand. I discouraged this, as I was not comfortable having folks pushing on the train on the uneven ground, fearing someone would slip and I'd be in a pot of trouble. But human nature is what it is, and I couldn't do much to stop the practice.
After getting the folks back inside, I'd fire up the engines and using as much power as I could short of slipping the wheels, would again try to mount the hill. Rarely, one such Do-Over was enough, more often it took 3-4 tries, with the train gaining several dozen yards each run before the power-traction curve got the better of me, making the wheels slip, losing all effective pulling power.
The one bright spot in this exercise was that one I made it around, and the rails were completely wet, I'd not have any trouble for the rest of the day. Likewise, if the rails started wet and the sun came out, the drying rails proved no problem.
The other related situation was at the end of the run when I entered the station. The platform canopy didn't completely cover the tracks but did tend to shield the rails from the worst of the rain, creating with the wet train wheels, the partially wet rail situation again. If I was not mindful of this, and I went into the station a bit too hot, when I applied brakes to stop, I risked locking up the wheels and sliding merrily past my parking position. (Remember, I didn't have the benefit of a reverse gear to correct that lapse). Locking up the wheels is as bad as slipping the wheels. It's again an ineffective, wet ice effect.
As this would be right in the view of George, the manager, not to mention the other ride operators, who seem to have long memories when one of us publicly screws up, I made it a point not to let that happen very often at all.
I think I learned a lot of practical physics being a train engineer!
(more later)
Dad
