Photos contributed by Neil A. Lieb

Of the slew of elevators Tillotson Construction Company put up in 1950, the one at Alta, Iowa, could have been considered a typical job, although the photo above shows that a sign company must have gone to work sinking anchors in the headhouse for the raised lettering. Built in the small Buena Vista County town that sits at the highest point on the Chicago-Illinois Railroad in its crossing of the Hawkeye State, the elevator followed Tillotson’s established Palmer Plan, with eight tanks of 18 feet in diameter rising to 115 feet in height. There was a 13-foot-wide driveway passing through the house in an opening 15 feet high under four split bins. An additional note about the Palmer plan says, “Extra dist @ Cupola and on Cleaner Floor,” and we take the abbreviation to mean distribution.

Here is the full list of specifications:

Capacity per Plans (with Pack) 246,070 bushels

Capacity per foot of height 2640 bushels

Reinforced concrete/plans (Total) 2082 cubic yards

Plain concrete (hoppers) 49.6 cubic yards

Reinforcing steel/Plans (includes jack rods) 112.4 tons

Average steel per cubic yard of reinforced concrete 107/96 pounds

Steel & reinforced concrete itemized per plans

Below main slab 9419 lb/91 cu yd

Main slab 32,077 lb/272 cu yd

Drawform walls 142,070 lb/1424 cu yd

Work & driveway floor (including columns) 1485 lb/30 cu yd

Deep bin bottoms 6682 lb/47 cu yd

Overhead bin bottoms 7929 lb/40 cu yd

Bin roof (corner) 10150 lb/51 cu yd

Scale floor (complete) none

Cupola walls 9655 lb/88 cu yd

Distributor floor 1912 lb/10 cu yd

Cupola roof 2753 lb/15 cu yd

Miscellaneous (boot, leg, head, track sink, steps) 2560 lb/13 cu yd (a note here in the plans says “Cleaner floor”)

Construction details 

Main slab dimensions (Drive length first dimen.) 60 x 73.5 feet

Main slab area (actual outside on ground) 4101 sqare feet

Weight of reinforced (total) concrete (4000#/cu yd + steel) 4276 tons

Weight of plan concrete (hoppers 4000#/cu yd) 99 tons

Weight hopper fill sand (3000#/cu yd) 708 tons

Weight of grain (at 60# per bushel) 7380 tons

Weight of structural steel & machinery 20 tons

Gross weight loaded 12,483 tons

Bearing pressure 3.04 tons per sq ft

Main slab thickness 24 inches

Main slab steel (bent) 1 in diameter at 7 inch o.c.

Tank steel at bottom (round tanks) 5/8 inch diameter at 6 inch o.c.

Lineal feet of drawform walls 762 feet including exterior

Height of drawform walls 115 feet

Pit depth below main slab 15 feet 0 inches

Cupola dimensions (W x L x Ht.) 23 x 61.5 x 39 feet

Pulley centers 161 feet

Number of legs 1

Distributor floor Yes

Track sink Yes

Full basement Yes

Electrical room Yes

Driveway width–clear 13 feet

Dump grate size 3 – 9 x 6 feet

Columns under tanks size 20 inches square

Boot — leg & head Concrete

Machinery Details 

Boot pulley 72 x 14 x 2 3/16 inches

Head pulley 72 x 14 x 3 15/16 inches

R.P.M. head pulley 42 rpm

Belt 14 inch 6 ply Calumet

Cups 12 x 6 inch at 8 inch o.c. Howell

Head drive 40 horsepower

Theoretical leg capacity (cup manufacturer rating) 8440 bushels per hour

Actual leg capacity (80 percent of theoretical) 6750 bushels per hour

Horsepower required for leg (based on above actual capacity plus 15 percent for motor) 33 hp

Man lift 1.5 horsepower electric

Load out scale Two 25 bushel Rich.

Load out spout 10.75 inch W.C.

Cupola spouting 10-inch diameter 14 gauge

Truck lift 7.5 horsepower Ehr

Dust collector system Fan → Dust bin

Driveway doors Two overhead rolling

Conveyor 14-inch R.H. 3 hp.