Darby-Savage Broadside Digger

DARBY - SAVAGE BROADSIDE DIGGING ENGINE 6 nhp.

A truly captivating and unique engine originally designed by Thomas Darby in 1888 and built by Savages of Kings Lynn. It has many unusual features, quite apart from its general layout. None of these original engines have survived the scrap yard. A wealth of information can be found in my father’s book, “Digging by Steam”.

There is nothing else on the market that presents such a fascinating model engineering challenge, in any scale.  It has a double ended boiler with a central firebox and twin smoke boxes and chimneys. 5 digging forks arranged along the boiler length. This 2” scale model was designed referencing the original drawings that were obtained from the last works manager of Savages and still in the possession of our family.

This model was designed and built by Colin Tyler and was awarded the Crebbin memorial trophy at the Model Engineer exhibition. It was also featured on Blue Peter. You can see this model in operation on Youtube. Look up TYLERDARBYDIGGER. There is a link in the left hand tool bar on this blog.

Serialised in the Model Engineer between April 1977 and May 1978 this engine is for the constructor seeking an entirely new concept in model engineering.

At the time of writing in 2011, there are two  models in existence. The first model (Colin Tyler’s) has ended up in a private collection in the USA, and the second, built by Pat Butcher is now owned by the Darby family.

DIGGER LEADING DIMENSIONS:

Length:       36” (0.91 Metre)                 Boiler Dia.                    5” (0.125 M)       

Width:        28.75” (0.73 Metre)             Flywheel Dia                 10” (0.254 M)

Height        21” (0.53 Metre)                  Working Pressure        75 psi

Weight       250lb (114 Kilo)                   No of Speeds                 2

DRAWINGS:       DS1            End General Arrangement

                             DS2            Front General Arrangement

                             DS3            Boiler

                             DS4            Cylinder

                             DS5            Motion

                             DS6            Drive Shafts

                             DS7            Motion & Cylinder Assembly

DS8            Shafts & Gears

DS9            Horn Brackets & Plates

DS10          Plate Layouts

DS11          Fork Mechanism

DS12          Wheels

DS13          Land Cart

DS14          Details

DS15          Typical Bearing

DS16          Chimney

Complete set of drawings referenced ‘Darby Digger Drgs’ at £116

CASTINGS:

REF #	DESCRIPTION	MATERIAL	QTY	£ EA	£ SET
D1	CYL BLOCK-WITH CAST VALVE PORTS	CAST IRON	1	134	134
D2	CYLINDER BLOCK TOP COVER	BRONZE	1	23	23
D3	CYLINDER COVER - REAR	BRONZE	1	18	18
D3A	CYLINDER COVER - FRONT	BRONZE	1	15	15
D5	FLYWHEEL	CAST IRON	1	82	82
D6	MIDDLE FORK (7 TINES)	CAST IRON	1	64	64
D7	MID/OUTER FORK (6 TINES)	CAST IRON	2	58	116
D8	OUTER FORK (5 TINES)	CAST IRON	2	58	116
D9	LANDCART WHEEL HALF	CAST IRON	8	15	120
D10	OUTSIDE WHEEL HALF	CAST IRON	2	78	156
D11	INSIDE WHEEL HALF	CAST IRON	2	74	148
D12	FINAL DRIVE GEAR	CAST IRON	2	55	110
D13	CLUTCH DOG HOUSING	CAST IRON	2	28	56
D14	CHIMNEY (CORED)	ALUMINIUM	2	52	104
D15	DISC CRANK	BRONZE	2	28	56
D17	FORK CRANKSHAFT BRKT-LARGE	GUN METAL	2	36	72
D18	FORK CRANKSHAFT BRKT-SMALL	GUN METAL	2	24	48
D22	SPLIT CRANK	BRONZE	1	36	36
D23	DRIVE SHAFT ECCENTRIC GEAR BRKT	GUN METAL	1	67	67
D24	DRIVE SHAFT BOTTOM HOUSING	GUN METAL	1	68	68
D25	REV QUAD & GOVERNER MNT BRKT	BRONZE	1	48	48
D26	CROSSHEAD GUIDE SUPPORT BRKT	BRONZE	1	40	40
D27	LANDCART FRONT UPPER STEER BRKT	GUN METAL	1	46	46
D28	LANDCART FRONT LOWER STEER BRKT	GUN METAL	1	37	37
D29	LANDCART AXLE FORK BRKT	GUN METAL	1	47	47
D30	L/CART AXLE FORK FLOATING BRKT	GUN METAL	1	28	28
D33	DRIVE SHAFT ANGLED BEARING-UPPER	BRONZE	1	24	24
D34	DRIVE SHAFT ANGLED BEARING-LOWER	BRONZE	1	17	17
D35	DRIVE SHAFT UPPER BRKT	GUN METAL	1	42	42
D36	DRIVE SHAFT LOWER BRKT	GUN METAL	1	38	38
D37	CRANKSHAFT BRKT-SMALL	GUN METAL	1	24	24
D38	CRANKSHAFT BRKT-LARGE	GUN METAL	1	45	45
D41	CAST FIRE BARS	CAST IRON	1	46	46
D43	LANDCART ADJUSTER BRKT	BRONZE	1	54	54
D44	LANDCART BRKT	BRONZE	2	27	54
D46	LANDCART LOCATION FORK	BRONZE	2	33	66
D47	LANDCART ADJUSTER BRKT-SMALL	BRONZE	1	26	26
D50	MAIN DRIVE SHAFT END BRKT	BRONZE	2	40	80