Graph of Output & Workforce - Equipment - The Irthlingborough Adit - Red Book Notes 1920 - Kilns - Charges to men - Company Farm tenants - 1919 E.V. wages - No.s 1 & 2 pits - Electricity Generating System - 1919 cost to get 1,000 tons - Explosives - Stocks Irthlingborough & Finedon - Costs of Land - Tractor Movements 1920 - Explosives Test - Output from kilns - Wages 1920 - Record of six day's work with Blackett Drill

560 Wagons purchased at outset.
3 foot gauge, (0.91 m.) tare weight 15 cwt (.68 kg.) nominal capacity 2 ton 10 cwt. (2.54 tonnes)
Still in use when the mine closed in 1965
14 British Electric Vehicles – Battery operated ‘tractors’ purchased between March, 1918, and February, 1922.  They each weighed 2 tons (2.03 tonnes), two were fitted with 4.8 hp motors and the remainder were 2 hp vehicles.   These replaced ponies used in the early years.
2 Trolley locomotives bought from America circa 1916 & refurbished by the General Electric Co.   These were the main haulage vehicles used to draw the trains of ore to the surface.   They were powered by a 240 volt D.C. supply through overhead trolley wires with the return current through the rail track.
6 ’Blackett‘ drilling rigs purchased circa 1920.
The main mine tunnel was approximately ¾ mile (1.2 km.) long, brick-lined and accommodating twin 3 foot (0.92 m.) gauge tracks with water channel below.   Driven to a rising gradient, into the mine, of 1 in 210.
5 foot diameter (1.52 m.) Sirocco ventilation fan driven by a 15 hp motor built over shaft No. 2, capable of extracting air at the rate of 100,000 cu. ft. (2832 cu. m.) per min.
Miner‘s equipment :-
Carbide lamp, pick, shovel, fork, and wooden stemming rod.
Carbide, chalk, dynamite, detonators and fuse cable.
The materials and equipment were purchased by the miner from the Company by deduction from wages. Safety helmets and safety boots were not worn at this time. (1920‘s)
Each miner usually worked with a mate called a helper and they were provided with hand operated Conqueror and Elliot ratchet drilling machines. With this method of drilling a man could be expected to load no more than 8 tons (8.13 tonnes) in an 8 hour shift.
Normally the miner was paid weekly based on the tonnage filled and it was left to him to pass on to his helper the amount due.
In the early days, however, and probably until the mid 1920‘s they were paid on a daily rate along with all other workers.
Surface buildings at outset:-
Workshops including electrical workshop
power house
carpenter's shop
clock house
fitting shop
Laboratory (single storey) with medical room and pay office
Explosives magazine
Steam locomotive shed
Trolley locomotive shed
Water softening building
Electrical generating plant consisting of 2 Galloway boilers and 2 Bellis & Morcam High Speed Engines of 150 and 250 K.W. capacity generating 250 volts D.C.
Steel brick-lined chimney
One weighbridge for mine wagons
Two weighbridges for main line railway wagons
16 "Gjers" type calcining kilns, 30 feet (9.1 m.) in height and 23 feet (7 m.) inside diameter.
Pine Lodge (existing house on Wellingborough Road) converted for office use
Employment Numbers and Occupations at the Mine in 1952
Senior StaffSinter Plant Personnel
General Manager1Charge Hands3
Mine Manager1Sinter StrandIgniters2
Under Manager1Labourers20
Surveyor1Feed Hands4
Electrical Engineer1General Operators2
Mechanical Engineer1TrommelMixerOperators2
Sinter Plant Superintendent1
Chemist1Hotel Staff
Foreman Fitter1Cook1
Office Manager1Kitchen Staff etc.5
Hotel Manager1Cleaners (part time)5
Hotel Manageress1
Office PersonnelMine Personnel
Secretary to General Manager1Deputies7
Surveyor‘s Assistants2
Electricians (Charging Station)
Shorthand Typist1Electric Trolley Loco Drivers6
Wages clerk1Battery Loco Drivers21
Chemist‘s Assistant1Road Repairers9
General Clerks4Labourers27
Office Cleaner (part time)1Miners (hand loading)30
Miners' Helpers30
Surface PersonnelMiners (special driveages)4
Weigh Clerks2Blackett Drillers8
Yard Foreman1Shot Firers (mechanical)4
Workshop foreman1Loader Operators4
Electricians6Hose Boys4
Fitters4Road Repairers (mechanical)4
Blacksmith’s Strikers6
Bricklayers (Mine & Estate)4
Power House Attendants2
Steam Loco
Fireman (Stoker)1
Estate Maintenance Workers3
Ropeway Attendants (working on Bank)5
Plate Layers (Surface) (laying track)2
Plate Layers' Assistants (Surface)2
Cook's Assistant1
Excavator Driver1
Lorry Driver1
Total number 282
After 1976 the developers of the Pine Trees area covered over the brick structure of the Mine entrance ’Adit‘, but its position is recorded as follows :-
The National Grid co-ordinates are:-
493,973.940 m E, 269,877.946m N.
The floor level is 192.7 feet (58.73 metres) above ordnance datum.
The positions of the shafts which were sunk 30 feet (9.138 m.) to the east of the line of the tunnel were as follows :-
Shaft No. 1 (downcast) :-
493,586.279 m E, 270,298.402 m N.
Shaft No. 2 (ventilation shaft) :-
493,356.378 m E, 270,539.795 m N.
The tunnel was driven on a National Grid bearing of 316º 23‘ 44" and the maximum internal width is 14 feet (4.27 m.).

(the above items may be added to, from time to time, as more information is confirmed or comes to light)
Miscellaneous (raw) notes extracted verbatim from Manager‘s notebook written circa 1920.
N.B. Notes have been added in RED to correct known errors, and for explanation (figures are in imperial measurements only as in the original).

The above system using the Blackett drilling rig had problems in that too much small material was produced when attempting to drill the whole face at one go.