When, where, and what equipment gave the smoothest ride?

[Overmod]

M636C

The trucks developed by Nystrom in the 1930s and 1940s were indeed very good. These looked superficially like the standard Pennsylvania equalised truck but in fact the beam linking the axleboxes was a separate subframe which located the axles and there were no normal hornguides.

Someone needs to find and link a copy of Nystrom's own observations on high-speed truck design (I'll keep looking for mine) where he points out that his true high-speed designs were all hard-riding below their peak design range -- this for the same predictable reasons variable control of disc brake anti-slide systems was necessary. 

This is one of the things that large, relatively soft secondary air-bellows suspension was intended to address: it allowed the necessary very stiff effective spring rate in primary suspension needed for proper flange following, while keeping the resulting bounce and NVH isolated from the carbody.

I do not know how much of the French craze for 'silentblocs' in the '50s could be attributable to Milwaukee practice.  We had a lesser, but still significant turn toward elastomer isolators (and Fabreeka, all the way into the mid-Seventies) in our own practice ... but with far more emphasis on accommodating bad track than on running quickly on good.

[M636C]

I do not know how much of the French craze for 'silentblocs' in the '50s could be attributable to Milwaukee practice.  We had a lesser, but still significant turn toward elastomer isolators (and Fabreeka, all the way into the mid-Seventies) in our own practice ... but with far more emphasis on accommodating bad track than on running quickly on good.

The other name was of course Dunlop Metalastik...

These became significant in North America on MLW's alternative to the Trimount, most often known as the Dofasco after the foundry that cast them.

These were designed for CN with the specific intention of reducing the lateral loading in curves, specifically that from the leading axle of of the trailing truck. So MLW moved the pivot right forward and sat the frame on four rubber/metal sandwiches. It rode really well when new but as the lateral dampers wore it tended to be rough.

But on taking over MLW, GE adopted the rubber secondary design for their "Rollerblade" trucks and EMD went the same way....

Peter

[SD70Dude]

The Dofasco trucks from retired M-liners were reused on the GE C40-8M cowls of both CN and BC Rail.  They are some of the roughest riding units we have, but I couldn't say how much of this is due to the truck and locomotive design (heavy safety cab and cowl carbody) vs age. 

The ex-BNSF/UP Dash-8's ride terribly too...

On the other hand SD60's aren't too bad (just loud and drafty inside the cab), and the SD75's ride like Cadillacs.

One advantage of the Dofasco truck is their shorter wheelbase due to closer spacing of the axles, which allows units with them to run on several of our branchlines where all other 6-axle units are prohibited. 

Also, Dofasco = Dominion Foundry & Steel Company.  Still doing business in Hamilton.

[Jones1945]

Overmod

Someone needs to find and link a copy of Nystrom's own observations on high-speed truck design (I'll keep looking for mine) where he points out that his true high-speed designs were all hard-riding below their peak design range -- this for the same predictable reasons variable control of disc brake anti-slide systems was necessary. 

Found some Patents drawings of Nystrom's high-speed truck:

http://www.freepatentsonline.com/2350567.pdf

(horizontal stabilization absorbers, rubber padding to reduce noise and vibration)

http://www.freepatentsonline.com/2431072.pdf

 

 http://www.spookshow.net/trucks/nystrom.html 

 

 

[mvlandsw]

"Mention was made of a smooth ride on a Pittsburgh PCC.   This was very poasible with most of the PCCs on most of the system.  But tthere some spectacularly bad-tracj sections, one center-reeervation stretch (Ashland Avenue?  It began with an A, and was east of the downtown area, toward the junction where one changed to the sparce service to Trafford), where the car jounced from side-to-side, and the  operator limited the speed to about 15mph.  A situation never repaired until the Allegainy Port Authority bustitution."

That was the Ardmore line.

[Overmod]

Peter, you might want to comment on the specific use of elastomer components in the FB-2 ZWT GE trucks that predated the 'Rollerblades'.  There are a very large number of these in various axes in the structure, many of which I always suspected would suffer the same 'taking a set' and deterioration seen in so many Mercedes driveline elastomer pieces 

[Mr. Bighead]

I always thought the older double-deck C&NW commuter coaches rode well. I'm not sure of their model or nomenclature and I'm sure they're all long retired. I rode them during their service years, and also the preserved ones once or twice on the Delaware River Railroad excursion. The old Bel-Del roadbed doesn't compare to the old Northwestern main, but those double deck cars still rode smoothly.

[Overmod]

M636C

The other name was of course Dunlop Metalastik...

They weren't anything but John Bull until 1958.  And most of their design emphasis as I recall was on vibration isolation, not indeterminate-rate shear springs... I'm glad to learn they had a significant railroad 'presence'.

Was Dunlop heavily involved in the 'chevron spring' craze of the Seventies?

[M636C]

Was Dunlop heavily involved in the 'chevron spring' craze of the Seventies?

They were indeed. The well known track interaction expert Jury Koffman tried to sell me a design using such suspension components from Gloucester C&W.

I explained to him that we had enough trouble with such springs on track maintenance machines and that the high UV content of sunlight in the Pilbara caused rapid deterioration of rubber springs. Since we had pretty good track with fairly broad curves we didn't break many coil springs and they didn't deteriorate faster in bright light.

I did tell him that we'd like to test some really heavy duty rigid frame coil primary suspension trucks from Gloucester. They never did sell any to mining companies but a lot of their trucks ended up in the East Coast coal export traffic, possibly due to my suggestion. Gloucester's salesman looked me up in WA later that year.

There were a few locomotives with floating bolster trucks in the Pilbara, all of the three axle variety. They gave a harder ride than the Alco Hi Ad but were better on rough track (which BHP inherited from the Goldsworthy operation) I think that the rubber elements weren't as exposed to sunlight as the chevron springs.

I remeber checking out the maintenance base of a rail grinding operation that used grinding vehicles built in Italy. These had rubber chevron springs and Deutz air cooled diesel engines. Next to the track there were neat walls of discarded chevron springs and Deutz diesels, the latter three engines high...

Peter

[M636C]

Jones1945

 

 

Overmod

Someone needs to find and link a copy of Nystrom's own observations on high-speed truck design (I'll keep looking for mine) where he points out that his true high-speed designs were all hard-riding below their peak design range -- this for the same predictable reasons variable control of disc brake anti-slide systems was necessary. 

 

 

 

Found some Patents drawings of Nystrom's high-speed truck:

http://www.freepatentsonline.com/2350567.pdf

(horizontal stabilization absorbers, rubber padding to reduce noise and vibration)

http://www.freepatentsonline.com/2431072.pdf

 

 http://www.spookshow.net/trucks/nystrom.html 

 

Neither the prototype truck nor the model truck illustrated here follow the Nystrom design clearly indicated in the patent drawings. The model truck retains the axlebox hornguides clearly absent from Nystrom's design in the patent, which became the prototype for the French high speed locomotive hauled trains.

Peter

[agentatascadero]

The original poster asked about ride quality back in the days when trains were operated with heavyweight equipment.

 

I'm one who rode, in my childhood, annual transcontinental trips between 1947 - 1955, nine total such trips, with 8-10 days aboard the train on a typical 2-3 week trip.  So, I spent many weeks aboard Pullmans, going seemingly everywhere on those trips.

 

One has to remember that things were very different in those post war years, railroads were generally maintained to a high standard, as was the passenger equipment, so smooth riding was to be expected, and was delivered.

 

Being passholders, we rode the secondary trains, which, in those years were still provided full service, with dining and lounge service , and we had the blessing of Pulman passes during those years.

 

My perch, was the upper berth....though many nights I was allowed to occupy the lower while my parents visited the lounge for nightcaps.  I'd fall asleep in the lower and never wake up until the next morning in the upper.

 

To this day I regard the sound of 6 wheel trucks, on jointed rail,  to be the standard by which all other railroad truck sounds will be measured.

[Miningman]

Thank you agentatascadero. I suspected that heavyweight 6 wheel Pullman's and the like on passenger service maintained roadbed was the best ride. It is something that is lost to us. Modern technology may be able to create a smooth ride here and there but it is as I well thought, the best of the best.