Fast Train, c. 1930

More of my interest in time-travel. So how fast were passenger trains in the US c.1930? Where they amongst the fastest in the world?

More to the point, what was the limiting factor on passenger train speed in that era? How could it have been overcome?

That is to say, given the technology of the time, and massive investment, how much faster could trains have been made to go? Was any interesting technology just on the verge of invention that might have helped?

Well the world record for the fastest steam train still stands, Mallard in 1938

https://en.wikipedia.org/wiki/LNER_Class_A4_4468_Mallard

The speed limiting factor was the heat build up in the main bearings - lubrication was very difficult to achieve.

So, if you can solve that problem with modern bearing seals and modern rotating seals then you would have a good chance of exceeding that speed.

Trains certainly ran routinely over 100mph into the 1950’s

You may find this article interesting:

Basically, trains in the 1930s were faster than they are now.

The article also goes into a lot of detail about why modern trains are slower.

Thank you. It is bedtime here. I will check back on Christmas morning. Ho! Ho! Ho!

Are there better looking steam trains than Gresley’s A4s? I think not.

The A4s were withdrawn from service in the early/mid 1960s, so possibly the East Coast Main Line was seeing 100mph+ until then?

Flying Scotsman - an A3 - hit 100mph in 1934, becoming the first steam train to do so. (There’s a chance City of Truro - a City class - reached 102mph on a mail run in 1904, but that’s disputed)

Trains in other parts of the world are faster than they were in the 1930s; the poor state of American train transport is not unique to the USA, but it is pretty poor compared to Eurostar or Shinkansen.

If you get a chance to see interiors of 1940s or 1950s passenger cars, they often have a speedometer mounted that went up to 100MPH.

Deltics (diesel-electric locos) replaced the steam A4s in the 1960s, and were capable of exceeding 100mph;
https://en.wikipedia.org/wiki/British_Rail_Class_55#Performance
these were replaced by the HSTs, which were scheduled to travel at 125mph. Current trains travel at up to 140mph on the same line.

I was on a German ICE this year - the digital display in the coach tells you how fast the train is going. In this case we were cruising at exactly 250kph.

One should note, though, that was specifically a speed record attempt. It’s a demonstration of the limit of technology, but not representative of speeds achieved by scheduled trains. Also, I think American railroads rarely (if ever) do these speed record attempts.

I believe the fastest British scheduled train of the era was the Flying Scotsman, a non-stop service from London to Edinburgh (392 miles). In 1932 the scheduled time was 7 hours 30 minutes, so that’s an average speed of 52.3 mph.

This article talks about American train speeds. Two railroads competed on their NYC-Chicago routes, and the article says in 1932, the run was scheduled for 18 hours. That’s 53.3 mph average. In 1935 they switched to a 17-hour schedule (56.4 mph).

So I think it’s safe to say that American trains in the 1930s were the fastest in the world, even if they did not hold the world record for top speed.

There was an electrified train called the Brill Bullet that was tested at 100 MPH. It entered service on the old Philadelphia & Western line that was intended to be the start of a long distance rail company but ended up as a commuter line. In 1989-1990 I used that line for a year. The Brill Bullets were being replaced in early 1990. Although the article: https://en.wikipedia.org/wiki/Philadelphia_and_Western_Railroad says the bullet trains were regularly used at 80-85MPH, by 1989, they didn’t exceed 60MPH. I know this because I often sat in the rear driver seat (they were double ended and had no turnarounds) and could watch the speedometer. Whether the reduced speeds were due to the rails or the cars, I don’t know.

So 100MPH was possible in 1931. I don’t any current US service can make such speeds today.

If you are talking steam power, the limiting factor would be the RPM of the driving wheels. Steam trains were reciprocating engines.

Exactly. The principal difference between freight steam locomotives and passenger steam locomotives of the same era and tech was drive wheel diameter.

In effect the vehicle has fixed one-speed “gearing”. Freight engines had relatively small drivers for high starting torque with concomitant low top speed. Whereas passenger engines had relatively large drivers for high top speed with concomitant lower starting torque.

In the beginning of diesel and ICE powerplants in locomotives there were efforts to build them with drive shafts and transmissions akin to then-current cars & trucks. That proved unreliable at the power levels needed.

Fortunately the electric traction motor which combined high starting torque and high top speed in the same box came along to solve that problem. And is still the go-to solution today in locomotives as well as making inroads in powering automobiles.

There was a tv show about Mallard breaking the world record, the limiting factor was heat build up in the main bearings because it was difficult to lubricate, and not the gearing, size of wheels etc

They were talking to the train driver.

On the Mallard heat build up may have been a problem. But today with ball bearings oil lubricated or in a oil bath heat build up would not be the problem. But there is a limit to the speed of a recip before it will begin to pound itself apart.

That was a weakness of that particular class locomotive (Gresley A4). From Wikipedia:

Part of this is the level of decrepitude we’ve let our rail network get into. It ciosts a lot of money to maintain the track - did you know that a single plain old wood railroad tie is about $50, and a single spike is about a buck, and modern ties and fixation methods are generally even more expensive? But some parts of it are simply inexplicable - does anyone remember the “2 hours and 59 civilized minutes” Amtrak DC/NYP ads from before the Acela? It’s now 3:24 on the Regional, 2:44 on the Acela. For the money spent on Acela, you’d think it would save more than 15 minutes.

When you dig into things, there are often a complex of inter-related factors. For example, the NYC Subway ran far more trains per hour (TPH) in the past than today, on lines that are seeing equal or greater demand now than back then. Why? First, they switched from asbestos brake shoes to non-asbestos ones. These increased stopping time / distances. This eventually led to accidents because the signal system was built based on the previous, better, braking performance. The level of training and autonomy of train operators has been going down, so they try to shift some of the control away from the T/O. “Full parallel” (the fastest mode of operation) was disabled on some types of equipment, lowering the maximum speed. They then added some station timer (ST) signals to allow trains to move closer to each other at low speeds near stations (which helped), but then they added wheel detector (WD) signals that can catch you even if you’re past the signal head, so operators creep over them, removing the ST advantage and making things even slower (if the next one you can see is blinking, you may have angered the one you’ve moved past). That’s the part that’s understandable, even if it doesn’t seem to be a good idea. But the speed benefits promised for the new CBTC system (for automatic operation) still don’t get things back to the number of trains per hour operated in the past.

BTW, speaking of bearings - a week ago I was using a 100-year-old tool to pull old bearing skein out of 102-year-old trolley axle boxes. Think of the most disgusting floor mop yarn you could imagine, soaked in grease and packed into a tight space so it is one solid mass of gunk. This stuff needs to be pulled out and replaced at scheduled intervals (usually mileage, sometimes time) to avoid bearing wear.

But what limits the RPM of the driving wheels?

For what it’s worth, the Mallard’s drive wheels (6’8" diameter), when setting the 126.4 mph record, would have been rotating at 531 rpm.

I’m partial to the Hudson J-3a with the Dreyfuss streamlining, myself.

Technologically, trains can run much faster today than they did in the 1930s, but it requires a lot of investment, mainly because the tracks need to be designed to support high-speed traffic. In the United States, the political decision has been not to come up with that money, but other countries in Europe or Asia have come up with high-speed train networks with cruising speeds of up to ~200 mph. Technology is not the limiting factor here.