Section 4. Construction of the Automotive Department Assembly Plant and Koromo Plant
Item 4. Description of the Koromo Plant
The plant layout drawings for the first phase of construction of the Koromo Plant, which was completed in November 1938, are as shown in Figure 2-1. The site area was approximately 500,000 square meters, and the building area was approximately 200,000 square meters. Total construction costs were 45 million yen.
As can be seen in Table 1-5, the Koromo Plant was an integrated production plant that included all processes necessary for automobile production including casting and forging blank processes, machining, mechanical assembly, stamping, body assembly, painting, and overall assembly. Each process was laid out so they were connected, and the Koromo Plant formed the basis of future plants.
Table 1-5. Facilities of the Koromo Plant (1938)
Category |
Plant |
Products |
Dimensions (shaku) |
Area (tsubo) |
Area (m2) |
---|---|---|---|---|---|
Casting |
Special casting plant |
Cylinder blocks, cylinder heads |
138×276 |
1,058 |
3,491 |
〃 |
Ordinary casting plant |
Transmission cases and other parts |
78×501 |
1,085 |
3,582 |
〃 |
Forgeable iron casting plant |
Differential cases and other parts |
90×501 |
1,252 |
4,133 |
〃 |
Annealing plant |
Forgeable iron cast product heat treatment |
366×90 |
915 |
3,019 |
〃 |
Coring plant |
Various cores |
138×150 |
575 |
1,897 |
〃 |
Wooden mold plant |
Wooden molds for cast parts |
72×204 |
408 |
1,346 |
〃 |
(No. 2 special casting plant) |
(Cast crankshafts) |
(108×300) |
(900) |
(2,970) |
Machining |
Tool and machine plant |
Tools and machine tools |
120×390 |
1,300 |
4,290 |
Forging |
Forging plant |
Rear axle shafts, knuckle arms, connecting rods, gears, and other parts |
84×384 |
896 |
2,956 |
〃 |
Tempering plant |
Forged product heat treatment |
96×144 |
384 |
1,267 |
Machinery |
Machining Plant No. 1 |
Engine part machining |
168×360 |
1,680 |
5,544 |
〃 |
Assembly Plant No. 1 |
Engine assembly and testing |
168×270 |
1,260 |
4,158 |
〃 |
Machining Plant No. 2 |
Transmission and steering part machining |
168×360 |
1,680 |
5,544 |
〃 |
Assembly Plant No. 2 |
Transmission and steering assembly |
168×270 |
1,260 |
4,158 |
〃 |
Machining Plant No. 3 |
Suspension part machining |
168×360 |
1,680 |
5,544 |
〃 |
Assembly Plant No. 3 |
Suspension part assembly |
168×270 |
1,260 |
4,158 |
Plating |
Plating plant |
Plating |
96×180 |
480 |
1,584 |
Heat treatment |
Quenching plant |
Carburizing and carbo-nitriding, annealing |
108×270 |
810 |
2,673 |
Stamping |
Stamping plant |
Stamped parts |
120×570 |
1,900 |
6,270 |
Auto bodies |
Autobody plant |
Autobody plate processing and body assembly |
240×720 |
4,800 |
15,840 |
Painting |
Paint Shop No. 1 |
Frame and suspension part enameled baked on paint |
42×450 |
525 |
1,732 |
〃 |
Paint Shop No. 2 |
Small component lacquer application |
66×450 |
825 |
2,725 |
〃 |
Paint Shop No. 3 |
Body painting |
90×450 |
1,125 |
3,712 |
Assembly |
General assembly plant |
Passenger car outfitting (second floor), truck chassis assembly and passenger car assembly (first floor) |
120×450 |
1,500 |
4,950 |
×2 |
×2 |
×2 |
|||
Inspection |
Adjustment plant |
Inspection of completed vehicles and chassis and adjustment |
120×90 |
300 |
990 |
Repairs |
Repair plant |
Paint touch up |
36×156 |
156 |
514 |
- Note:
- Parentheses indicate facilities constructed after 1938.
With regard to the continuity of the processes, various transport conveyors were installed in sand processing facilities and casting sand transport systems in the casting plant as well as the painting plant and the final assembly plant with the aim of flow production based on the Just-in-Time system (see Item 5.). Initially, a conveyor system was not installed in the machining shop, but overhead space was provided in the plant building and electric lines and steam and compressed air pipes were placed in underground pits or on poles to avoid interference with other facilities when a conveyor was later installed and secure the space needed for a conveyor.
In addition to these direct production facilities, the plant also included a test track, forging (blacksmithing) shop, maintenance shop, warehouses, a cafeteria, and more. The engineering divisions included the Administration Office (including the Engineering Officers Office), Design Office, Chemical Testing Office, Vehicle Testing Office, Aircraft Research Office, Photo Office (Drawing Office), and Prototype Office. In addition, the site also included a head office Administration Office, dorms, a school (to train technical workers), and other administrative and benefit-related facilities.
Kiichiro Toyoda made the following statement concerning the significance of the Koromo Plant: