Intersting reading with historical diagrams.....
http://www.freepatentsonline.com/2350567.pdf
Had no idea until I read this that the truck had horizontal stabilization absorbers or used rubber padding extensively to reduce noise and vibration. I'll bet the horizaontal stabilization made a difference at higher speeds when going through rough switches with dampening the sideways back and forth.
Nystrom did a lot of work in high speed passenger car trucks in the 30's and early 40's. My guess is that absorbers and rubber padding are to reduce hunting at high speeds.
- Erik
MILW passenger cars equipped with Nystroms were said to be some of the smoothest running.
C&NW, CA&E, MILW, CGW and IC fan
One thing Nystrom himself mentioned was that a passively-stabilized truck that was smooth riding at high speed was harsh at slower speeds (below about 40 mph, iirc). This is unsurprising when you think about it, but bears remembering (including for operation 'in preservation').
Wizlish One thing Nystrom himself mentioned was that a passively-stabilized truck that was smooth riding at high speed was harsh at slower speeds (below about 40 mph, iirc). This is unsurprising when you think about it, but bears remembering (including for operation 'in preservation').
What is the source for that remark of Nystrom's? I did find this summary of comments made by one of Nystrom's assistnts. He says the hi-speed trucks have "excessive vertical amplitude on rough branch lines when operated at low speeds." https://books.google.com/books?id=RAidPrpZUNQC&pg=PA507&lpg=PA507&dq=Nystrom+truck&source=bl&ots=VOhntJm-hB&sig=EfQCvHuTmW-fZ-THOdiK_qFRI3A&hl=en&sa=X&ei=HAGIVdmVA5CzyASXwrTADA&ved=0CCUQ6AEwAjgU#v=onepage&q=Nystrom%20truck&f=false
Patents: http://www.freepatentsonline.com/2431072.html
https://www.google.com/patents/US2347362
Even if he did make that remark, it would probably only be true for jointed rail where there is some low-joint-high-center condition, even though tiny, right after several uses after surfacing. It would probably not be true for continiuous welded rail.
schlimm Wizlish One thing Nystrom himself mentioned was that a passively-stabilized truck that was smooth riding at high speed was harsh at slower speeds (below about 40 mph, iirc). This is unsurprising when you think about it, but bears remembering (including for operation 'in preservation'). What is the source for that remark of Nystrom's?
What is the source for that remark of Nystrom's?
You have me doubting my own memory now. I don't recall the original reference coming from White's book ... but I remember it being in list form, very much like the one that is there. And I do seem to remember the point about the swing hanger being overrated.
On the other hand, I also seem to remember that part of the 'argument' was that additional spring stiffness was required (together with much stronger and quicker damping) for high speed in 'contemporary' service, and this made the ride choppy at slower speeds. That might mean that the spring rate of the (relatively) soft secondary vertical springing could not be 'optimized' for low vs. high speed with periodic "input" from rail jointing.
https://milwaukeeroadarchives.com/MilwaukeeRoadMagazine/1947July.pdf
Karl Fritjof Nystrom was born in September 1881 in Aspa Bruk, Sweden, a small village dominated by an iron works. He was thrown largely on his own resources at the age of 14, working during his school vacations and living on an extremely modest scale. He was graduated from the Mining School at Filipstad, Sweden in 1904, as a mechanical engineer. He was at the head of his class and was awarded a prize of 500 kroner. During his college career he spent summer vacations working in machine shops in Stockholm and steel mills in other parts of the country.
After graduation he went to Germany to study high tensile steel, but soon decided to follow up his studies in this country. He arrived in 1905, with practically no knowledge of the English language, and was immediately attracted to Pittsburgh, the center of the steel industry.
Mastering the English language and getting started in industry was no easy task. He worked as a blueprint boy and then as an engineer for the Midland Steel Company, later taking a job with the American Steel & Wire Company, still at a bare subsistence wage. Overwork made him an easy target in a typhoid epidemic and for months he was confined to a hospital.
Upon recovering he became a draftsman for the Pressed Steel Car Company. Later he was engaged as a member of the engineering staff of the Pullman Company. In the latter part of 1909 he went to the Southern Pacific during the electrification of its Oakland-Alameda interurban line and designed and supervised the construction of the first electric interurban cars for that service. Following this in 1911, he was made assistant mechanical engineer of the American Car & Foundry Company. He was mechanical engineer of the Acme Supply Company in 1912-13 and by that time was well launched on his career.
In 1913 he became chief draftsman of the car department of the Grand Trunk, now the Canadian National. He accepted a similar position with the Canadian Pacific in 1918, but in 1920 returned to the Grand Trunk as engineer of car construction.
In 1922 he was appointed engineer of car design for the Milwaukee Road and has been with this company ever since. He was promoted to engineer of motive power and rolling stock in 1925 and served as master car builder from July to September, 1927, at which time he was advanced to the position of superintendent of the car department. In 1937 he was promoted to the position of mechanical assistant to the chief operating officer, with general supervision of the car department, as well as supervision of engineering, designing, construction and co-ordination of facilities in the mechanical department. On Sept. 1, 1941, his jurisdiction was extended to include all branches of the mechanical department. Effective Jan. 1, 1945 his title was changed to chief mechanical officer.
Mr. Nystrom has close to 100 patents to his credit, but possibly his principal claims to distinction are the development of welded lightweight freight and passenger car construction and his highly successful experimentation with passenger car trucks.
https://news.google.com/newspapers?nid=1368&dat=19610606&id=9G1QAAAAIBAJ&sjid=qxAEAAAAIBAJ&pg=7186,2995194&hl=en
Wow, he is buried in the Hartland, WI cemetary close to the ROW of the Milwaukee Road Chicago to Twin Cities mainline. I wonder if he planned that?
This is an interesting design. Instead of relying on the pedestal to to guide the axle bearing vertically and prevent it from moving either in yaw or side-to-side, it uses those two sets of links, connecting the truck frame to the axle bearing through rubber bushings.
The concept of using links or rods set in bushings is prevalent in European and Japanese high-speed passenger and locomotive trucks. It is found in the Genesis locomotives trucks and the Superliner I. The Superliner II and the Horizons and everything-else-besides Amfleet appears to use a "pedestal truck" having the "metal-on-metal" guiding that the patent claims is important to avoid.
One more thing: the patent appears not to show any side-motion device such as swing hangers to carry the truck bolster. Maybe this detail was left out because the patent is claiming trucks without or without this form of "secondary" suspension? The photos and drawings I have seen of Milwaukee Road coaches show swing hangers and secondary-suspension springs, if I remember correctly.
I am guessing that instead of letting the axle box slop around inside the pedestal guide, especially as it wears, that there are adjustable or maybe self-adjusting wedges? Anyway, Amtrak appears to not like the sort of thing depicted in the patent or any innovation in truck design, it seems.
If GM "killed the electric car", what am I doing standing next to an EV-1, a half a block from the WSOR tracks?
There is good discussion of Nystrom's truck designs in the excellent book "Hiawatha, Nothing Faster on Rails" published in 2014 by Milwaukee Shops Inc. (there is a predecessor volume by them, "Hiawatha, First of the Speedliners," about the 1934 Hiawatha and the developments that lead up to it. Both volumes although pricey are worth the money and are urgently recommended to those with a taste for getting into the details of how a great train was developed, and then improved, from the ground up.
In a discussion on page 24 not of the Nystrom trucks per se, but about Nystrom's experiments in 1935-37 at improving four wheel truck design working with GSC, the knee-action triple bolster truck of 1935: "At speeds between 55 and 65 mph, violent verticle vibrations occured. Also the stability of the truck was not acceptable." In late 1937 Nystrom experimented with an American version of the Gorlitz truck, again working with GSC. "There was no definite improvement in riding quality over the predecessor knee-action truck." I assume that means it was also rough riding at the "slower" speeds.
But neither of those experiments was what became known as the Nystrom truck per se, although I suspect some patents were applied for based on Nystrom's work on them. The book indicates that the experiments with these trucks helped Nystrom refine his thinking about four wheel high speed trucks that resulted in the 1938 (and later 1942) "Nystrom" trucks.
Dave Nelson
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