by Typewriters
For those interested in manufacturer information on the historic Universal series locomotives, I've started this new string. Allen Hazen should be particularly interested.
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7FDL-16 Engines / Domestic U-Series
The 7FDL-16 engine had subletters to designate models, and numbers following that to designate variants. From the 1977 UX (Unit Exchange) manual we find the following listed model information for Domestic (United States) Universal series road locomotives only.
U25: 7FDL-16A2, A3 and A5
(Note: Other materials in my collection tell us that there were more variants; these are probably just those that GE was offering replacements for, The hint here is that A1 and other variants may have been deleted from locomotive fleets and replaced with variants as seen here. Also, the very first advertising brochure for the U28 described the diesel engine for that series as the 'latest improvement on the 7FDL-16A3 engine, but it's clear that GE decided to redesignate the new single exhaust pipe, steel cylinder head insert engine as the C series.)
U28: 7FDL-16C1 through C8
U30: 7FDL-16D1 through D7
(Note: After the U30 had been in production for some time, the U33 appeared. From that point on, U30 and U33 locomotives received variants of the same engine in the E series.)
E Series Engines
U33: 7FDL-16E1, E2, E3, E4, E5, E9, E10, E12, E14, E15, E16, E17, E20
U30: 7FDL-16E6, E7, E8, E11, E13, E18, E19, E21
F Series Engines (U34 and U36)
U36: 7FDL-16F1, F3, F5
U34: 7FDL-16F2, F6
G Series Engines (U30, U33, P30) These are the CHEC excitation engines, with unique components.
U30: 7FDL-16G1, G3, G6, G7, G8, G9
U33: 7FDL-16G2, G4, G5
P30: 7FDL-16G6
H Series Engines (3600 HP CHEC excitation)
U36: 7FDL-16H1, H2
The 12 cylinder engines do not appear to follow the 16 cylinder engines, as I've noted before, in chronological sequencing and letter application. The domestic U23 series and the U50C have engines in various 7FDL-16C, D, and F series. The specific engines for the U50C were the 7FDL12D1 and 7FDL-12D4.
REBUILT ENGINES offered by GE were sourced from the pool of traded in engines and/or engines submitted for the Unit Exchange program. The program was complex, but basically operated this way: Owners of fleets who wished unit exchange for six units or more could obtain engines rebuilt at GE in the UX series, and send in their own engines as trades. In this "normal" form of the program the owner DOES NOT receive back his own engines rebuilt, but rather engines from the program. There was provision to have an owner's engines sent in and rebuilt as well.
Rebuilt engines were built to a given "replacement standard" designated by GE, which in most cases included upgraded components - either because the original components were out of production, or because the newer components were more compatible with more recent production (which eases spare parts supply.) So, for example, several of the rebuilt variants offered as straight replacements for engines for the U25 series incorporated steel crown pistons which in actual chronological production had not appeared until the introduction of the F engine for the U36. (Steel crown A series replacement engines were the 7FDL-16A3R2, 7FDL-16A3R3 and 7FDL-16A3R5.) Speaking still of replacement engines in the A series, GE listed the A3R5 variant as the Primary stock model, with the A3R1 occasionally in stock. The other variants (2 through 4) would be built upon request. These had varied other features.
It is worth noting that GE was not offering in the rebuilt A series engines, apparently, the original true "one piece" cylinder assembly. All that were being turned out were the steel cylinder head insert type that had originally appeared with the preproduction U28 locomotives and became the 7FDL-16C series in domestic U-boats. I will have to look, but recall seeing in an engine overhaul manual the mention of the eventual non-availability of the original A series style assemblies and provision for substitution of the C or later type when railroads were ordering replacement parts.
Anyway, that's enough for now. I have lots more to add in further posts that'll go into the various rebuilt engine packages. Also there'll be posts on other equipment through the U series line as I dig it out of the pile of manuals I've got around here.
For those unfamiliar with the FDL model designations I suggest the four part series I did years back on our locomotive blog. Search for the FDL engine articles: http://railroadlocomotives.blogspot.com/" onclick="window.open(this.href);return false;
-Will Davis
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7FDL-16 Engines / Domestic U-Series
The 7FDL-16 engine had subletters to designate models, and numbers following that to designate variants. From the 1977 UX (Unit Exchange) manual we find the following listed model information for Domestic (United States) Universal series road locomotives only.
U25: 7FDL-16A2, A3 and A5
(Note: Other materials in my collection tell us that there were more variants; these are probably just those that GE was offering replacements for, The hint here is that A1 and other variants may have been deleted from locomotive fleets and replaced with variants as seen here. Also, the very first advertising brochure for the U28 described the diesel engine for that series as the 'latest improvement on the 7FDL-16A3 engine, but it's clear that GE decided to redesignate the new single exhaust pipe, steel cylinder head insert engine as the C series.)
U28: 7FDL-16C1 through C8
U30: 7FDL-16D1 through D7
(Note: After the U30 had been in production for some time, the U33 appeared. From that point on, U30 and U33 locomotives received variants of the same engine in the E series.)
E Series Engines
U33: 7FDL-16E1, E2, E3, E4, E5, E9, E10, E12, E14, E15, E16, E17, E20
U30: 7FDL-16E6, E7, E8, E11, E13, E18, E19, E21
F Series Engines (U34 and U36)
U36: 7FDL-16F1, F3, F5
U34: 7FDL-16F2, F6
G Series Engines (U30, U33, P30) These are the CHEC excitation engines, with unique components.
U30: 7FDL-16G1, G3, G6, G7, G8, G9
U33: 7FDL-16G2, G4, G5
P30: 7FDL-16G6
H Series Engines (3600 HP CHEC excitation)
U36: 7FDL-16H1, H2
The 12 cylinder engines do not appear to follow the 16 cylinder engines, as I've noted before, in chronological sequencing and letter application. The domestic U23 series and the U50C have engines in various 7FDL-16C, D, and F series. The specific engines for the U50C were the 7FDL12D1 and 7FDL-12D4.
REBUILT ENGINES offered by GE were sourced from the pool of traded in engines and/or engines submitted for the Unit Exchange program. The program was complex, but basically operated this way: Owners of fleets who wished unit exchange for six units or more could obtain engines rebuilt at GE in the UX series, and send in their own engines as trades. In this "normal" form of the program the owner DOES NOT receive back his own engines rebuilt, but rather engines from the program. There was provision to have an owner's engines sent in and rebuilt as well.
Rebuilt engines were built to a given "replacement standard" designated by GE, which in most cases included upgraded components - either because the original components were out of production, or because the newer components were more compatible with more recent production (which eases spare parts supply.) So, for example, several of the rebuilt variants offered as straight replacements for engines for the U25 series incorporated steel crown pistons which in actual chronological production had not appeared until the introduction of the F engine for the U36. (Steel crown A series replacement engines were the 7FDL-16A3R2, 7FDL-16A3R3 and 7FDL-16A3R5.) Speaking still of replacement engines in the A series, GE listed the A3R5 variant as the Primary stock model, with the A3R1 occasionally in stock. The other variants (2 through 4) would be built upon request. These had varied other features.
It is worth noting that GE was not offering in the rebuilt A series engines, apparently, the original true "one piece" cylinder assembly. All that were being turned out were the steel cylinder head insert type that had originally appeared with the preproduction U28 locomotives and became the 7FDL-16C series in domestic U-boats. I will have to look, but recall seeing in an engine overhaul manual the mention of the eventual non-availability of the original A series style assemblies and provision for substitution of the C or later type when railroads were ordering replacement parts.
Anyway, that's enough for now. I have lots more to add in further posts that'll go into the various rebuilt engine packages. Also there'll be posts on other equipment through the U series line as I dig it out of the pile of manuals I've got around here.
For those unfamiliar with the FDL model designations I suggest the four part series I did years back on our locomotive blog. Search for the FDL engine articles: http://railroadlocomotives.blogspot.com/" onclick="window.open(this.href);return false;
-Will Davis