Driving Wheels and Frame Reunite

It has been over four months since the last Chicago & North Western #1385 steam status update was posted. What has been happening on the locomotive in that time? The short answer is quite a lot.

SPEC Machine, located outside of Middleton, Wisconsin, continues to serve as the center of the action under the care of SPEC’s Steve Roudebush and the 1385 Task Force. Work continues on a near daily basis inside the well-equipped shop. Several different tasks are in progress at any given time, allowing for work to continue no matter what hurdles are thrown in the way.

Here are the latest areas of the project undergoing work.


Replacement of the footplate was a time consuming task but is finally complete. The footplate sits between the frame underneath the cab and serves as the connector between locomotive frame and drawbar, thus massive forces are transferred through the footplate when pulling a train. The original footplate casting, already repaired in the past, was found to have more cracks and was deemed unsafe to attempt further repairs. A new weldment was manufactured. It is now fully mounted to the frame using tapered bolts to ensure no movement.

CNW 1385 footplate

CNW 1385 installed footplate.

Lead Truck

The lead truck is almost fully disassembled. Pins and bushing of the swing link suspension were found to be badly worn and require replacement. The holes in the truck casting where the swing link suspension connected were also worn well out of round and will require welding up and reboring. Inspections also found the bolts holding the jaws to the truck loose, allowing axle wear if left uncorrected.

The wheels are being assessed whether they can be turned on a lathe and machined to a proper profile. All wheels were well worn, but only one wheel exhibited significant wear to the flange, but possibly not too much as to not be fixed with a session on a lathe. If turning the wheels are possible, it would save what could be a rather involved process of trying to locate a suitable replacement wheel or wheels.

Crown Brasses

Four out of the six driving wheels’ crown brasses were found reusable after machining. The remaining two had to be replaced with new brasses due to being too thin according to American Locomotive Company and C&NW specifications. The reused brasses are expected to be able to be turned once or twice more before they too require replacement.

Spring Rigging

The spring rigging is fully installed. New pins and sleeves were installed throughout. Some had been replaced in the past using improper material which caused excessive wear not only to the pins and bushings, but also caused excessive wear to other spring rigging components. Some of the beams were found to be worn thin enough to cause concerns over the safety of welding up and reboring. Instead those equalizing beams were replaced with new custom fabricated beams.

The springs underwent a deflection test. All springs proved to have near-equal deflection, meaning they are all equally good or equally bad. Equality among spring deflection is desirable so as to avoid one set of springs taking on more weight than the others.

Rod Brasses

The rod brasses fit inside the locomotive rods and accept the wear associated with the movement of the rods (which serve to connect the wheels to the piston and to one another so that driving force can be applied).Four out of twelve brasses were found to be in serviceable condition. They were machined and reinstalled. The remaining eight brasses were replaced with new brasses machined on the lathe.

Delays were encountered in this process due to the materials taking time to arrive and subsequent computer hiccups with the CNC machine. Fortunately, the malfunction did not occur while machining the expensive brasses. Following the computer’s sudden bit of moodiness, substantial testing of the repaired CNC machine followed prior to resuming brass work.

Valve Cages

Valve cages fit within the valve bore and house the valves which control the admission of steam into the main cylinders. The fireman’s side valve cage was found to have broken pieces requiring replacement of the cage. Cuts to the cage were made to allow for its removal. The engineer’s side valve cage was found to be serviceable and is undergoing reboring.

The use of the CNC milling machine on the brasses is an example of using recent technological advancements to repair the historic C&NW 1385. However, when it comes to reboring the valve and cylinder bores, the 1385’s team have gone decidedly old school by bringing out Mid-Continent’s Underwood Boring Machine, a tool nearly as old as the locomotive it is repairing.

C&NW 1385 project volunteer Pete Deets explains the operation of the Underwood Boring Machine in the following video.

Driving Wheels and Rods

In early November, volunteers descended on SPEC Machine to help with the task of reattaching the newly cleaned and polished rods to the driving wheels and getting them back under the frame. This is no small task as the main driver weighs in at a hefty 15,000 lbs. and each of the two other drivers weigh roughly 10,000 lbs. each. They first needed to be connected together with the also quite heavy side rods, and then all 35,000 pounds of driving wheels plus side rods rolled down the temporary track into position under the frame. Before this could happen, the frame and attached parts, well over 40,000 lbs. itself, had to be jacked up high enough for the wheels to pass underneath. This was accomplished through a hydraulic jack and carefully constructed cribbing. Volunteers involved include Richard Potthast, Mike Wahl, Ed Ripp, Kyle Gherke, Guy Fay and Pete Deets.

Photographer Brian Allen was on hand the day the drivers were rolled under the frame. His Flickr album from the day can be seen by clicking the image below.

Upcoming Tasks

The steel side plates for the cab (where the locomotive lettering appears) were produced in October. With these in hand, it is possible to begin drilling holes into the wooden cab components for final assembly and painting. Cab repair and reconstruction is being carried out by CJ Woodworking at their facility with plans to move the finished cab, when complete, to SPEC Machine.

The other major component of the locomotive still ahead is the boiler. Currently 2D drawings are being converted into 3D CAD files which Deltak, the manufacturer of the new boiler, can then use for production. This work was previously being done by volunteer Jeff Westphal. Unfortunately, life can get in the way of volunteering and Jeff had to step down from this role. This and other delays have caused the boiler to not yet reach production stage at this time as was predicted earlier in the year. Despite this, progress on the 1385 as a whole continues at a steady pace. Once the drawings are complete, they will be sent to an independent third party for expert review before beginning production.

With boiler production nearing, your financial help is needed to allow work to continue at the steady pace enjoyed thus far. Gifts both large and small are vital to covering the cost of boiler production and remaining shop work to get C&NW #1385 under steam again. Visit the Donation page to learn how you can contribute toward the C&NW #1385 project.

Driver Repairs Continue at Strasburg Rail Road

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 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

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

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:

Sandblasting of Running Gear In-Progress

Sandblasting of C&NW No. 1385’s running gear began on Thursday, January 16th at the SPEC Machine shop in Middleton, Wis. All three sets of drivers were sandblasted along with one pallet of parts. Work was done by Howard Grote & Sons of McFarland, Wis. The chassis was to be sandblasted on Friday the 17th, but Mother Nature intervened with temperatures in the teens causing the hoses and air lines to freeze up. The unfinished sandblasting was rescheduled for Monday, January 20th, but as of the time of writing this post, temperatures are predicted to be similar to that on the 17th.

Sandblasting is used to help remove all the past accumulated rust and layers of paint. Exposing the bare metal makes inspections of the parts much easier and more accurate as as layers of rust, paint and grease can serve to hide cracks and other defects which need to be identified at this stage of the restoration.

A Howard Grote & Sons employee works through the snow and cold to sandblast the a set of drivers belonging to C&NW No. 1385. Click on the image to browse more photos from January 16 on photographer Brian Allen’s Flickr album.

BEFORE (photo taken January 11, 2014)

AFTER (photo taken January 17, 2014)