Tag Archives: wheels

Driving Wheel Repairs Completed

Mid-Continent Railway Museum Posted on by

Late January marked the return of Chicago & North Western No. 1385’s driving wheels to Wisconsin after nearly 10 months away. All three sets of the locomotive’s 63-inch drivers were sent to Strasburg Rail Road on March 24, 2014 to receive a range of repairs using Strasburg’s specialized machinery and expertise in the field of completing such repairs. Here is a rundown of the repairs which encompassed approximately 350 man-hours of labor.

wheel diagram

Wheel Centers

Wheel centers are equivalent to the rims of an automobile. It the main bulk of the wheel and includes the central ‘boss,’ spokes and rim.

C&NW 1385 last received wheel work in 1994, four years before its final summer of running in 1998. Mid-Continent’s record of repairs from 1994 show that three of the tires were removed and wheel centers inspected at that time. They were 0.160, 0.127, and 0.124 (inches) out of round. By turning the tire seats on Strasburg’s wheel lathe it returned the wheel centers to perfect roundness and eliminated the need for wheel shims.

The wheel centers were also inspected using magnetic particle inspection, or ‘magnafluxing.’ It is a non-destructive testing process to detect surface and near-surface discontinuities in some metals. A few minor cracks were located in the process. To enact repairs, a steel sample from a wheel was taken and a welding procedure specially tailored to the wheels’ metallurgical properties then devised and completed.

Hubliner

Hubliners are metal disks that are mounted on the inward-facing side of the wheel centers and are designed to absorb the wear where contact occurs between the wheel and the driving boxes. While at Strasburg, one of the six hubliners was replaced while the remaining five were all refaced to provide a smooth, even surface.

hubliner and journal detail

Journals

Journals are the portion of the axle, just inside the wheels, where the weight of the locomotive rests.

No. 1385’s journals were found to have scratches and other minor issues. Polishing was attempted but the imperfections were found to be too deep. To bring the engine to mainline-ready condition, the journals were turned and then polished to produce a smooth surface.

By making adjustments to the journal, it was also was necessary to make corresponding adjustments to the journal boxes. The journal box is what transfers the weight of the locomotive from the frame to the axle. Inside the box is a crown brass, shaped to fit over the top of the axle. The crown brass must be a perfect fit so as to allow just a film of journal oil to form between the journal and the crown brass and thus prevent overheating from friction.

With the final dimensions of the journals now known, the driving boxes were sent to a local shop in Baraboo, Wis. to machine the crown brasses. Inspection revealed one of the six brasses worn beyond accepted limits and that brass has been replaced. The other five proved to have sufficient material left to provide a long service life.

Replace Crankpins

Crankpins transfer forces between the rods and wheels. The forward and rear drivers have smaller crankpins because they only connect to the center (main) driver via side rods. The main driver has a larger crankpin because it connects to both side rods and the main rod. To offset the weight of the larger crankpins and rods, the main driver requires a heavier counterweight.

crankpin detailThe main crankpins and the crankpins on the rearmost driver were found to be worn beyond American Locomotive Company’s standards and were replaced. The crankpins on the first driver were in good enough condition to allow for machining in order to renew the bearing surface.

 

Quartering the Crankpin Holes

In order to work properly, a driving wheel must be offset (rotated) by exactly 90-degrees from the wheel it is connected to via the axle on the opposite rail. As 90-degrees is one-quarter turn of a wheel, the process is called ‘quartering.’ The holes to receive the new crankpins were bored and then the crankpins themselves were machined in such a way as to maintain exact quartering.

Installing New Tires

Similar to how tires on a car are designed as readily replaceable items designed to absorb the wear of going down the road, a tire on a locomotive fits over the wheel center and is designed to absorb the wear of rolling down the railhead and use of the locomotive’s brakes.

Project volunteer, Ed Ripp, adds some detail:

“The tires that were on the wheels were the tires that were originally on the engine when it came to Mid Continent [in 1961]. The running gear work that was performed in [1994] included just re-profiling the tires, not replacement. With just 1,000 miles or so of running since then, some significant flange wear on one tire developed that was near FRA wheel profile condemning limits. In order to bring that one tire into compliance, all of the other tires have to be turned to the same diameter. This is due to the fact that the drivers are coupled together with the side rods.”

As a result, No. 1385 received new tires for all six wheels so they could all be equal in size with a lot of life to avoid the need for another round of maintenance in the near term. Several hardness levels are available from which to choose when having tire made, based upon expected usage and environmental factors. No. 1385 received Grade C hardness tires.

stack of locomotive tires

In order to prevent the tires from coming off in operation, they are custom ordered to fit down to within thousandths of an inch. They are sized approximately 1/16 inch smaller than the wheel center onto which it must fit. They are then heated to cause expansion, enabling them to slide into place. Once cooled, the fit becomes tight. Strasburg Rail Road took a video of the process and it is available for viewing on their YouTube page.

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Return to Wisconsin and Painting

Following completion of repairs at Strasburg Rail Road, the drivers were trucked to SPEC Machine where they arrived on January 22, 2015.

 

More images of the arrival of the driving wheel are available on photographer Brian Allen’s Flickr page.

Within a few days, the wheel centers along with various spring rigging components were painted black.

Meanwhile, progress has been made on the driving boxes and the beginning of reassembly of the running gear, but that will have to wait until another post.

Driver Repairs Continue at Strasburg Rail Road

Mid-Continent Railway Museum Posted on by

Work on C&NW 1385’s three sets of 63-inch driving wheels continues. Work is being carried out by the Strasburg Rail Road shop facility in Pennsylvania. Here is a run-down of the status of the drivers as of an October 13, 2014 communication from Strasburg to Mid-Continent’s 1385 Task Force:

  • The #1 driver crankpins are turned and only in need polishing.
  • The #3 driver crankpin hub faces are welded up.
  • The new R3 crankpin (#3 driver, engineer side) is pressed in and ready to be riveted over on the back side.
  • The old R2 hubliner (#2 driver, engineer side) has been removed, its mounting studs are center punched, and ready to be drilled out. New hubliner material is on hand.
  • A crack near the R2 crankpin hub has been chased out and welded up.
  • The R2 crankpin hole has been bored out.
  • The new R2 crankpin is being machined.
Diagram

Diagram showing driving wheel arrangement on a R-1 class steam locomotive. Driving (powered) axles are numbered front-to-back and specific wheels on the axles are defined as being on the left or right side. For example, L3 refers the wheel on the left side (fireman side) of the third powered axle.

The estimated completion date for the driving wheels is the end of 2014. The biggest influence of whether the target will be met is uncertainty of the lead time for the delivery of new tires. The order of operations is to press all new crankpins in, then turn the tire seats on the wheel centers. The new tires will then be ordered to fit snugly to the final dimensions of the wheel centers.

See the March 30, 2014 post for a further explanation of wheel centers and tires.

Driving Wheel Overhaul Underway at Strasburg

Mid-Continent Railway Museum Posted on by

On March 30, 2014, C&NW 1385’s three sets of 63-inch driving wheels were shipped from Wisconsin to the Strasburg Rail Road in Pennsylvania in order to be “turned” on a lathe, receive new tires, and have other adjustments and repairs completed (scroll down to the March 30th post for additional detail). On the weekend of June 28, 2014, Mr. Bernard Krebs of Jim Thorpe, PA photographed the drivers for the benefit of this steam status page, allowing us a glimpse of the work in progress.

Strasburg Rail Road makes use of a 90-inch Niles wheel lathe originally sold to the Lehigh Coal and Navigation Company in 1912. Lathes of such sizes were commonplace in the major railroad shops of America when enormous steam engines commonly roamed the rails, but now are rare with a limited number of shops around the country capable of handling tasks of such size.

Modern railroad equipment still undergoes similar maintenance procedures but all feature smaller wheels. The electric traction motors used on modern locomotives make wheel size relatively unimportant compared to steam locomotives where wheel diameter directly impacted piston speeds.

During each full rotation of a driving wheel on a steam locomotive the piston and connecting rods change direction of motion twice (forward then back). This very rapid change of direction puts a large amount of stress on the parts involved. Therefore, increasing the distanced traveled per wheel revolution and thus reducing the number of back-and-forth piston motions per second was an important design feature for high speed operations. It is no coincidence that the Milwaukee Road Class A and Class F7‘s that were built for 100 MPH-plus running of the Hiawatha trains between Chicago, through nearby Wisconsin Dells, and on to the Twin Cities featured massive 84-inch driving wheels. The British LNWR 2-2-2 3020 Cornwall is an extreme example of this concept, featuring 96-inch driving wheels.

Per Wikipedia, “Freight locomotives generally had driving wheels between 40 and 60 inches in diameter; dual-purpose locomotives generally between 60 and 70 inches, and passenger locomotives between 70 and 100 inches or so.” Compare C&NW 1385’s drivers with those of Saginaw Timber Company No. 2 as an example. In order to attain a speed of 60 MPH, No. 2’s 44-inch drivers would require roughly 7.6 revolutions per second while No. 1385, built for fast freight and secondary passenger service, features 63-inch drivers that would require roughly 5.3 revolutions per second. Worded differently, it means the 1385 can travel 30% farther using the same number of piston motions. The Class A or Class F7’s 84-inch drivers meanwhile would only require a comparatively leisurely 4 revolutions per second.

Driving Wheels Depart for Strasburg

Mid-Continent Railway Museum Posted on by

Chicago & North Western No. 1385 turns 107-years-old today! That is worthy of celebration with a new steam status update.

The reach of the restoration work on Chicago & North Western No. 1385 is expanding. Restoration work on various parts of the locomotive has already or is anticipated to take place in shops in Middleton and Fond du Lac, Wisconsin as well as Plymouth and St. Paul, Minnesota. Now components of Mid-Continent’s star locomotive will be traveling even farther from home for restoration work. On Monday March 24, 2014, 1385’s 63-inch driving wheels were loaded on to a semi-trailer for shipment to Strasburg, Pennsylvania. Upon arrival the drivers will again be inspected and a repair plan will be finalized with one of the nation’s premier steam restoration shops, the Strasburg Rail Road.

Driving wheels are usually designated by number, counting upward while moving from the front of the locomotive back toward the cab. A specific wheel can be designated by referring to it as the right side (engineer‘s side) or left side (fireman’s side). For example, No. 1 driving wheel, right side would be the driving wheel farthest forward on the engineer’s side. Simply referring to the No. 1 driver usually infers the wheels on both sides plus the connecting axle. The No. 1 and No. 3 drivers on the 1385 each weigh about 10,000 lbs. The No. 2 driver is the main driver, meaning it is the driver connected to the pistons providing the power. The No. 1 and No. 3 drivers are not directly connected to the pistons but are instead connected only to the main driver via connecting rod. The larger crank pin (cylindrical protrusion) on the main driver necessary to host these connections along with the accompanying larger counterweight needed means the main driver weighs an extra hefty 15,000 lbs.

View more recent photos:

Being sent to Strasburg Rail Road along with the drivers is a list of known repairs as well as items for further inspection. While the entire scope of work needed is not yet known, the following items will be addressed.

The drivers will each be receiving a new set of tires. Steam locomotive tires are a removable ring of steel, usually weighing several hundred pounds, that surround each wheel center. Just as a tire tread on an automobile wears down from rolling along the highway and is designed to be replaced after a number of miles, the tire on a locomotive also wears down over time due to its contact with the railhead and brake shoes and must be reshaped and eventually replaced. Each of the six driving wheels will be receiving brand new tires during their stay in Strasburg.

Before the new tires are applied, the wheel centers will be turned on a wheel lathe. This process means a thin layer will be shaved off the wheel center (see below photos). By doing so, places of uneven wear or other imperfections will be removed, providing a uniformly smooth and round surface on which the tires can be mounted. As the tires are applied to the wheel centers they are heated which causes them to expand. They are then slid onto the wheel centers and gauged to ensure proper distance between the tires and proper placement on the axle before they cool. When the tires cool and shrink they will grip the wheel centers tightly and, with the freshly prepared surface of the wheel center, will not slip out of place during normal operation.

Worn tires are reprofiled on a wheel lathe at the Chicago & North Western 40th Street shops in Chicago in Dec. 1942. C&NW 1385's drivers will be turned on a wheel lathe similar to this one. Jack Delano photo. Library of Congress collection.

Worn tires are reprofiled on a wheel lathe at the Chicago & North Western 40th Street shops in Chicago in Dec. 1942. C&NW 1385’s drivers will be turned on a wheel lathe similar to this one. Jack Delano photo. Library of Congress collection.

A tire is heated so that it may expand and be fitted to the wheel center. Photo from Atchison, Topeka and Santa Fe shop in Shopton, IA, taken Mar. 1943. Jack Delano photo. Library of Congress collection.

A tire is heated so that it may expand and be fitted to the wheel center. Photo from Atchison, Topeka and Santa Fe shop in Shopton, IA, taken Mar. 1943. Jack Delano photo. Library of Congress collection.

Volunteer Nancy Kaney cleans one of 1385's drivers. Important parts are identified. See the Jan. 11, 2014 post for more photos from that day. Brian Allen photo.

Volunteer Nancy Kaney cleans one of 1385’s drivers. Important parts are identified. See the Jan. 11, 2014 post for more photos from that day. Brian Allen photo.

The hub liners, identified on the above photo, will also receive a final inspection at Strasburg.

The journal is the portion of the axle onto which the weight of the boiler, cab and everything else supported by the frame, rests. The weight is transferred from the frame to the journals via a driving box. Housed within the driving box is the crown brass, a bronze composition that wraps over the top of the journal. When moving, a thin film of grease prevents excessive friction between the two surfaces, but some friction does still occur. This is the reason the crown brass is composed of softer metal than the journal, to ensure the crown brass receives the majority of the wear. Crown brasses are more easily and cost effectively replaced. Despite these designs, the journal can still be subject to wear over time. The journals of the 1385’s drivers will be carefully inspected and reported on by Strasburg.

In the photograph of the driving boxes the crown brass is the bronze-colored arch seen inside the box. Also shown is the wear plate on the driving box. The wear plate is lined with babbitt which is a relatively soft material (like the brass) and bears on the hub liner of the wheel center during normal operation. The wear plate takes up the side-to-side movement of the axles and provides a relatively easily replaceable component during normal repair.

If no surprises are found by the Strasburg shop crew, the refurbishment of 1385’s drivers could be completed as soon as late 2014. When it comes to restoring historic railroad equipment though, not encountering a least a few surprises along the way might be considered… surprising.

Back at SPEC Machine, work will continue on the frame and additional running gear components. The latest activity has centered on the rear frame plate. On March 24, what the drawings refer to as the footplate was removed. This is a large steel casting at the tail of the locomotive frame that is bolted into the frame. The drawbar that connects the locomotive to the tender – and thereby the rest of the train – attaches to this casting so all the power the locomotive generates is applied to this point. Several cracks and major necessary repairs were found during inspection. The worst crack is highlighted in the photograph below. The cuts in the casting were part of the extraction procedure. For the safety of crew and passengers of future 1385-led trains, as well as to ensure long term operation, it was decided to replace the footplate.

View more photos of recent work:

Rebuilt Tender Arrives at Mid-Continent, Restoration Moves on to Next Phase

Mid-Continent Railway Museum Posted on by

This past weekend featured a buzz of activity on C&NW 1385. The tender tank, new (former freight car) trucks and frame were loaded first thing Friday morning (11/15) at DRM Industries. It was then trucked to Mid-Continent where a crane was waiting to place them under the rebuilt display structure north of the depot which also houses the Shay and narrow gauge boxcar.

While the wheels and frame were being placed, a second tractor-trailer arrived with the rebuilt tender tank. Beginnings around 11:30 a.m., the tender tank was moved into position and lowered onto the frame. Even though the tender is at North Freedom, is not quite done. Grab irons need installation, the rear headlight needs to be installed, the tank hold-down brackets need to be installed and bolted tight, and the tank interior needs the protective coating applied. Final touches will need to be completed when the tender is married to the locomotive. For now, it will enjoy prominent position under a covered display area while it waits.

Tender tank hoisted by crane

Photo by Brian Allen. Click on image to browse Brian’s entire Flickr album from the day.

The work on C&NW 1385 continued throughout the weekend. On Saturday loose parts were rounded up from their storage places and placed on shipping pallets. Then on Sunday, the crane was at work again, this time lifting the C&NW 1385’s running gear onto trucks for delivery to Spec Machine in Middleton, Wisconsin for restoration work there. The frame and two sets of driving wheels were loaded onto the first trailer around 2:00 p.m. The immense weight of these components required that one set of driving wheels and and the leading truck (i.e. the small wheels in the front that help steer the locomotive through curves) be separated, temporarily converting the 4-6-0 locomotive into a 0-4-0 wheel configuration. Project volunteer Pete Deets explains:

That conversion wasn’t by choice… On the day of the pick, the operator quit lifting at 84,000 lbs. and the running gear hadn’t budged from the rails yet. They dropped the front truck and the operator stopped again at 79,000 lbs. without lifting off. The #3 rods and driver were dropped and the lift was made at about 72,000-74,000 lbs. The truck and driver came in at 10,000 lbs. apiece.

The first tangible evidence of restoration progress returning to Mid-Continent was enough to entice reg in al media to come report on the 1385’s restoration, including a story by Capital Newspapers (publisher of Wisconsin State Journal) which includes interviews with Mike Wahl, Project Manager, and Don Meyer, former General Manager and now serve ring as the project’s fundraising consultant. There is also a nice video report by NBC 15, Madison’s NBC affiliate in which Pete Deets and DRM Industries’ Matt Hillmer do a great job conveying the challenges of the restoration and uniqueness of the 1385.

Our Steam Task Force team deserves a hand for delivering on the first major component of the restoration. They have put in countless hours in the nearly 2-1/2 years since the Wagner Foundation grant was announced, resuming the restoration. There is an even greater amount of work yet to do as the tender is only the first step in the returning of the 1385 to service. Aside from the running gear work alluded to earlier, the cab is about half done at a Fond du Lac woodworking shop. The new boiler will begin to be built after all the required calculations are complete to create the Federal Railroad Administration Form 4.

For things to continue humming along, continued financial support is needed. Please consider visiting our donation page to learn how easy it is to support the C&NW 1385 restoration.

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