Steam & Excursion > Getting up to Speed on Steam

Let's go back 60 years. The RDC is suddenly down and they pull a hot light 4-8-4 to pull 2 coaches. The steam engine has to meet the RDC schedule so a real need for rapid acceleration run like hell a few miles and brake hard and late at the next station. Your fireman is good and keeps full steam pressure. The line is relatively level with minor undulation. But for our sake, basically flat.

How will you get up to speed fastest?

Tominde Wrote:
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> Let's go back 60 years. The RDC is suddenly down
> and they pull a hot light 4-8-4 to pull 2 coaches.
> The steam engine has to meet the RDC schedule so
> a real need for rapid acceleration run like hell a
> few miles and brake hard and late at the next
> station. Your fireman is good and keeps full
> steam pressure. The line is relatively level with
> minor undulation. But for our sake, basically
> flat.
>
> How will you get up to speed fastest?

Only one real choice, i.e. heavy to full throttle starts, and hook her up as she requires. Doesn't sound much different than SP, or CB&Q commuter service, back in the day.

Hotwater will remember this:
On the NY&LB commuter RR, North Jersey Coast....

Because of so many stations,
very close together, accelerating with steamers was rapid and repeated.
The closeness of the stations below Red Bank, all the way to Bsy Head, made rapid starting and stopping critical --- so many following trains were in the 'que' .... both CNJ trains and PRR trains,,,, evening rush ours were wonderful, lots of trains crunched into about 3 hours...

Replicating that with diesel-electrics led to severe overheating of the passenger-geared diesels---- so the management lengthened the time allowed to make the trips.
Source: Railway Guides from the era....compare the timetables... South Amboy to Bay Head was about 18 minutes longer, in the diesel-era.... In fact, BEST diesels for the NY& LB was the Big Baldwins, with the really rugged Westinghouse propulsion---- Westinghouse's
Traction motors had more copper and were much stronger, Electrically, and could take the 'abuse' better.
The Baldwins had two 1,000 hp, 4-stroke cycle engines--- each one driving 2-traction motors... They did not match the K4s for getting up
to speed quickly, but they were better than the diesels with the lighter and less rugged traction equipment.

With a big 4-8-4, and a fully charged boiler, accelerating with two coaches would snap your next !! He'd almost be up to 50-per in 3-engine lengths...

The bigger problem is lack of braking capacity of the 4-8-4.
They were not designed for that kind of abuse.....so your hypo should be altered to lengthen the load to 4-6 coaches, for stopping power.

RDCs were light, but also only the two inner-most axles (one per truck) are powered....

They were powered by mechanical ( hydraulic) transmissions and a gear box on the driven axles...
They were prone to grease and dirt buildup on the wheel treads, such that, as single units, they would not reliably operate the signal systems for grade crossings and block occupancy.... They were equipped with disc brakes, only ---- and no tread brakes..
The remedy was was to install "wipers" the truck frames fitted with pdas to to bear on the wheel treads..kept'em polished...

So loaded RDCs were no great shakes, when it comes to speedy pick-ups...

I'd speculate that the steamer, properly 'loaded', would eat the RDC for lunch!

IMHO
W.

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Edited 1 time(s). Last edit at 07/11/17 15:11 by wcamp1472.

Makes me think of the "Nickelgrabber" which was our nickname for the MP commuter train between St Louis Union Station and Pacific, MO.
I would ride my bike down to our suburban depot every evening and marvel at how he would stop on a spot and then accelerate like a shot with the 4-6-2 and 5 commuter cars. I used to race it on my bike and after about 2-3 engine lengths was staring at the last car.
I miss stuff like that.

wcamp1472 Wrote:
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> RDCs were light, but also only the two inner
> axles are powered....
>
> They were powered by mechanical ( hydraulic)
> transmissions and a gear box on the driven
> axles...

Yeah, Wes, I run RDC occasionally on the North Shore Scenic. Surely not an acceleration queen! Most any steam engine would beat an RDC in a drag race.

-John

My group restored an RDC in New Jersey, and fact is, they are dogs in accelerating, and would be eaten alive by just about anything..our 18 ton Plymouth might even dust her off.......

"How will you get up to speed fastest?"

Why pop the clutch, while the throttle is open. Geezzz

"How will you get up to speed fastest?"

On O. Winston Link's Sounds of Steam Railroading, Vol. 1....
There's a track with a K-2, 4-8-2, leaving Luray(?). Va. At a very fast clip...you can hear the engineer get the power reverse up,to short cut-off in 2 steps..
The engine makes one or two driver revolutions, he's up,to speed, very quickly, with not a slip, or a quarter-slip.
Listen to that track..it'll mak a believer of you.

If it was me, I'd let the loco roll to a stop, with the sanders on, stopping on the sand...
With max, to very-high, boiler pressure, and a low level of water in the sight glass....while resting, I'd have the fireman get the fire nice and bright, with the rear coreners loaded with coal ( to keep from tearing holes in the firebed.... at the signal to start, I'd have the fireman start the injector , feeding water....
while also feeding the stoker at a slow steady speed,
Then with the cylinder cocks open, the sanders "on", and the valve gear in full forward position, I'd draw the throttle back, fill the cylinders with steam..
.then GO FOR IT !!!

After, a couple of driver revolutions, bring the reverser to mid-position,---- get a couple more revs, then rapidly move the reverser to its "sweet spot",
cut the sanders back, or off, open the throttle wider...and hold on, for dear life..

Again, I'd want a decent sized train for braking power....

Acceleration would be rapid, and thrilling., not a drag race, but very rapidly moving a couple of million pounds up to 60-per is astounding...

W.



Edited 1 time(s). Last edit at 07/11/17 18:54 by wcamp1472.

Guess that's how the CPR's Royal Hudsons covered the 24 miles between Kamloops and Pritchard BC in 24 minutes on a regular basis back in the day...with full size passenger consists no less!

CP didn't have the flashy power, nor a large fleet of articulateds (in spite of many miles of 2% grades) but the performances they got out of their engines argues that they didn't need them!

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Darren Boes
Lethbridge, AB
Southern Alberta Railfan

On a light train 2 cars, would you spend more time with reverser at say 60% cutoff and slowly work your way back to center or would you get better acceleration coming back toward center more rapidly? My gut says literally "play it by ear" regardless of the size of the train. The engine will tell you by sound when to "change gears". Not unlike driving a stick shift.

Tominde Wrote:
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> On a light train 2 cars, would you spend more time
> with reverser at say 60% cutoff and slowly work
> your way back to center or would you get better
> acceleration coming back toward center more
> rapidly? My gut says literally "play it by ear"
> regardless of the size of the train. The engine
> will tell you by sound when to "change gears".
> Not unlike driving a stick shift.

Depends on the locomotive. And yes, you "play it by ear", and maybe glance at the back pressure gauge, if there is one.

With such a light train, the cylinders will fill with steam quickly & the amount of the "load" is so light, you won't get much useful, especially, audible feedback.

It will be hard to get enough of a draft to make her bark...
Be ahead of the steam demand, hook her up quick, and be sure to not get the reverse too close to center---- you benefit from a good 'steam cushion'... Especially when lightly loaded....

We had the Big Berk on a 4-car train in bitter cold weather, Hagerstown, MD*, and could not a decent draft, to get a hot fire, quickly .... After several bad starts, we took it easy, before widening on the throttle... The Big Girl wouldn't have it any other way!

We coulda got to 60-per in about 3- engine lengths, with only 4 cars...

It didn't help, that we tried a tender full of power plant coal .... Size of un-popped popcorn ... OMG...

Was good fuel, but not for building a nice firebed --- took about 50 miles to get a decent bed.... Then things got better.

Never did make much stack noise though, which misled the crew.. Used too much steam and still no 'Bark'..

W.

Ask Doyle about the WM Ry
( winter) "Teachers' Special'.... 1971/72(?)...

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Edited 1 time(s). Last edit at 07/12/17 10:39 by wcamp1472.

> South Amboy to Bay Head was about 18
> minutes longer, in the diesel-era

Schedules in 1960 look to be a minute
or two slower than 1947. What years
are you comparing?

Time..

What1940 era Station-stops were eliminated from the most recent timetable?
( sample "Washington St.", in Long Branch? Manasquan, NJ?)....

W.

Schedules in 1960 look to be a minute
or two slower than 1947, for the same
number of stops. What years are you
comparing?