BLWcontrols

Baldwin / Baldwin-Lima-Hamilton control stands

It is fairly well known in railfan circles that many Baldwin and Baldwin-Lima-Hamilton diesel locomotives were built with air operated throttles, and as such could only operate with similarly equipped units. The actual story is more complicated than that; there were two different air throttles available over the years, and there actually was one electric throttle as well. Let's take a look at these and examine some of the differences.

Here is an illustration from Baldwin manual DS-107, which is the Operator's Manual for 660-1000-1500 HP Switchers, Revised 12-1-48. Yes, road switcher type locomotives which were not fitted with multiple unit controls were referred to in some early manuals as "switchers."

This control stand contains the simplest and earliest air throttle, which was known as the D-1 Controlair. The throttle handle is No. 24 on the drawing; the slot for insertion of the reverser is just below it. Pulling the throttle back towards the engineer results in the air throttle mechanism increasing air pressure in the "throttle pipe," which acts upon the governor on the engine to increase engine speed. In some units, there is also an air operated Carbonstat Load Regulator which serves to control generator loading which is also connected to the throttle pipe. In all units which use this D-1 throttle, also connected to the throttle pipe is something called a "K-3 Throttle Switch."

When the throttle is all the way forward, air pressure in the throttle pipe is zero. When it is pulled back, air pressure starts to rise; when it reaches 8 psi, the K-3 throttle switch closes. The throttle lever itself may, or may not, have a notch that you can feel it enter after it is pulled back a short angle from the idle position. This is called the "first notch" position --- but remember that through most of the motion of the throttle on any of these air throttles, movement is smooth with no notches. You can finely adjust power wherever you want it, which was advertised as a big advantage compared to 8-notch electric throttles.

In that "first notch" position, air pressure in the throttle pipe for a D-1 should be between 14 and 16 psi. Obviously, before this pressure is reached, the K-3 switch has closed, and power is being delivered. The engine is still at idle speed in the first notch position. Above this, as the throttle is opened, pressure rises until the throttle is wide open, at which pressure will be between 50 and 55 pounds. Some locomotives have yet another device connected to the throttle pipe, called a Field Control Switch, used to alter traction motor fields for soft starting. Many don't.

Here is a slightly different cab arrangement, still including the D-1 Controlair control stand and throttle. This is from Baldwin-Lima-Hamilton manual AS-101-A, Operator's Manual for Standard 1600-HP All-Service Diesel-Electric Locomotives with D-1 Controller and 6-SL Brake Equipement, Plus Modifications such as Multiple Unit Control, Dynamic Braking, CE-100 Control Stand, 24-RL Brake Equipment, Dual Control Stands, etc. (Yes, that's the full title of the manual from the title page!!)

The use of the D-1 control stand does NOT rule out having multiple unit controls. You can use this control stand with MU. However, this control arrangement cannot be used with any of the other optional throttles. The D-1 was the standard throttle, and the others (which are below) were optional based upon specified equipment or customer order.

The D-1 Controlair is the old, original setup. Inclusion of equipment designed later than the D-1 ended up requiring a new master controller, which could perform more functions. This new air throttle controller was known as the CE-100.

From the same AS-101-A manual is this shot. This is the CE-100 control stand, for units with multiple unit control and dynamic braking. Note that the controller itself is quite large, and is cylindrical. The throttle operator shaft comes straight out the top, with the bent throttle handle attached to a turret. The reverser is mounted in the controller below the throttle lever, on the front. It has either three notches, if the unit does not have dynamic brakes, or five notches if the unit does have dynamics. There may or may not be a latch on the lever which has to be released to allow it to move, but it also cannot be moved unless the throttle is all the way forward in "idle."

On the CE-100, right at the forward end of the throttle movement, there are two notches. All the way forward is idle, and right next to it is the "first notch position." On this throttle, this is actually an electric switch contained inside the throttle. It causes the main power contactors to close, which applies power to the traction motors. Pressure in the throttle pipe will be 8 to 10 pounds in this position.

With the CE-100, air pressure in the throttle pipe at wide open throttle is 60 to 65 pounds. There may or may not be three notches spaced out at the wide open end -- according to some manuals, these provide "running positions." The throttle lever is also used for dynamic brake control.

The CE-100 was, of course, used much more often on streamlined road locomotives. Let's take a look at pictures from two rare manuals.

The picture at left is from the New York Central Railroad Company Instructions for Operation of Diesel Electric Road Locomotives - All Classes, which was produced by the railroad in 1949. It shows the control setup for the "babyface" Baldwin road locomotives owned by the NYC. (Models DR-4-4-1500 and DR-6-4-1500.)

NYC owned exactly four sets of these units. All four sets were three-unit, A-B-A sets rated 4500 horsepower. Two of the sets contained B-B freight locomotives with dynamic braking. The other two contained A1A-A1A passenger locomotives with steam generators. The shot at left is generally applicable to both types, but is specific to the freight units, as the passenger units had a different gauge panel on the dash in front of the engineer -- seen below. Other controls were basically the same between freight and passenger types.

All eight of the cab units contained the CE-100 controller, modified for dynamic brake control (5-notch reverser) on the four B-B freight units.

This is a picture from an early manual for what are popularly known as "Shark" or "Sharknose" units. It is neither model DR-4-4-1500 nor model RF-16. Some explanation is necessary. (You've already noted the CE-100 controller, I'm sure.)

Baldwin changed over from the old, "babyface" body to the new, angular "shark" body in early 1949, and units of model DR-4-4-1500 with this new body were built until June 1950. Between June and November 1950 no units of this kind were built. When production began again, the units were not yet model RF-16 as is commonly assumed. They were model DR-4-4-1600. This shot is from the manual for these locomotives; below is further explanation from the standpoint of operator's manuals.

In May, 1950, Baldwin Locomotive Works issued manual number DF-105, which covered the last group of units delivered to the Pennsylvania Railroad. These units had some slight external differences as compared to previous "shark" units, but small external details are meaningless as regards model designation by the manufacturer. Internally, these units began to change over to equipment which would be necessary when the anticipated uprating of the units took place at some point. Changes began to be made to the auxiliary generator/exciter, for example. These units are frequently totally mislabeled in railfan circles as "RF-15" units, which model never existed as far as Baldwin was concerned. They were still model DR-4-4-1500.

When production was about to restart, which was the result of an order by the Baltimore & Ohio for 1600 HP road freight locomotives, Baldwin issued manual number DF-106. This manual was issued in October 1950. Manual DF-106 consists of the majority of the content of DF-105, plus the addition of green revision and update pages in the front of the manual itself indicating that the manual was originally published in May 1950 as DF-105 and that alterations in design and/or customer order had required modifications to the manual with revision as DF-106. The model of the locomotive is clearly given as DR-4-4-1600/1, which means that the normal railfan-published sequencing of model numbers at this time by Baldwin is completely incorrect. Following the merger with Lima-Hamilton, which occurred in November, 1950, the official model designations were simplified and changed, and at that time, model RF-16 replaced model DR-4-4-1600 as the main line road freight unit.

Now that we are all through that, here is the last kind of controller which was optional in Baldwin and Baldwin-Lima-Hamilton locomotives. It is difficult to find an actual Baldwin manual which shows this controller, so I've used my Lima-Hamilton manual 1200STD, for 1200 HP Diesel-Electric Switching Locomotives.

This is the Westinghouse XM-781 controller. It is an eight-notch electric throttle. It was available with or without MU and with or without dynamic brake. In MU applications, an extra selector lever like that in other brands was added; it would be sticking out of the top of the controller, behind the throttle lever. No. 7 is the reverser lever. This setup could be built with a number of MU cable and pin combinations to allow Baldwin (or B-L-H, or for that matter Lima-Hamilton or Fairbanks-Morse) units to operate in multiple with EMD or ALCO-GE locomotives with electric throttles. As you might assume, there's just no way to operate an electric throttle with an air throttle.

There you have it; all of the variants of Westinghouse throttles used in Baldwin and Baldwin-Lima-Hamilton diesel-electric units postwar. Hopefully, this page will clear up a lot of confusion about this kind of equipment in the railfan world!