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AB BOLINDER-MUNKTELL - A BRIEF PRESENTATION

The head office and main workshops of Bolinder-Munktell are situated in the town of Eskilstuna, centre of one
of the most industrial areas of Sweden. The steel manufacturing tradition goes back to the 15th century.

The Bolinder-Munktell Company is an example of a complete merger of two famous old firms – the Bolinder
Company and the Munktell Company.

The Munktell workshops were founded in 1832 by Johan Theofron Munktell.
Johan Theofron Munktell had studied production techniques in England. The manufacturing program started with lathes, steam engines and locomotives – the first Swedish steam locomotive was built by Munktell’s in 1843 – but agricultural machinery very soon became the most important product, comprising threshing machines, steam locomotives etc. – and since 1913 agricultural internal combustion engine powered tractors.

In 1844 two brothers Jean and Carl Gerhard Bolinder established a workshop and a foundry in Stockholm.
The two brothers had studied abroad and they utilised their Knowledge of modern production techniques in
their home country Sweden, where industrialisation was at an early stage of development. Bolinder
manufacturer started with steam engines and woodworking machines but already in the 1890’s the production included oil engines and the Bolinder engines soon became a great success on the world market. In the year1932 – one century after the foundation of the Munktell workshops the Munktell Company and the Bolinder
Company amalgamated with head office and workshops in Eskilstuna, where today every fifth person earns his
living directly or indirectly from AB Bolinder-Munktell.


From a mid 1950s Bolinder-Munktell presentation loaned by John Pattle.Retyped due to the poor condition of
the original.

Historical Summary of Bolinder’s Hot Bulb Oil Engines

In 1902 F.A.Rundlof invented the two-stroke crank-chamber scavenge hot bulb engine.
He passed the invention to Bolinder’s who had been building 4 stroke paraffin engines of up
to 30 hp since 1893. This was the beginning of a vast series of engines, of a type that can
be termed a ‘Two-Stroke Hornsby-Akroyd’.


1906 Direct reversing was patented. Like many other early oil engines Bolinder’s used hit and miss governing,
        the exception being the other manufacturers had linked the fuel pump stroke to the governor by 1920.


1908 The E type direct reversing engine was introduced in l, 2 or 4 cylinder form up to 320 hp.
         One contemporary account whilst stating ‘Bolinder’s had advanced far enough to employ timed injection
         of fuel for reversing their marine engines’ goes on to say ‘this arrangement can hardly be called
         positive reversing and, arrangement can hardly be called positive reversing and, moreover it is
         necessary to de-clutch from the propeller to accomplish the above, it however serves very well
         indeed for barge work and such like where these manoeuvres are of a delicate nature’. A contradiction
         in terms?

         The hot bulb was of a different form to that used in later engines, having a larger un-cooled
         area with the fixed arc sprayer injecting across the bulb into a horizontal cylindrical injection chamber.
         This greater un-cooled mass would overheat on full load unless cooled. This was accomplished by
         injecting water into the cylinder via the transfer passage. Boatmen preferred to run with the water drip
         off as it caused high cylinder wear. In theory the engines would not idle on No load without the lamp on.

         The hand adjustment of the fuel pump stroke for ‘no miss’ operation at cruising speed was introduced
         on this model. Running in this manner a fuel saving of 5% was claimed.


1914 The M type was introduced in a range up to 500 hp. With these engines, the water injection was replaced
         by compressed air. The engine drives an air compressor, the fuel being sprayed into the ignition
         chamber by the air blast which also acted as the cooling media. I believe I’m correct in saying that the
         M type was only available in the higher powers the E type continuing for low powers.


1921 The NE type was introduced, superseding all previous types. These were available in 6-500 hp range. With
        this type the variable arc spray was introduced, the hot bulbs remaining black in colour with the engines
        under full load. An increase in power of 10-30% was achieved over the previous types. With the NE the air
        damper (heater Box) was introduced on all but the smallest engines. These ere given double shoulder
        bulbs and earlier commencement of injection.

        Also in 1921 an electric starting device was introduced. This consisted of a flow plug, starting time being
        reduced to 30 seconds. I imagine that unless the engine was put on high load immediately it would go out
        unless the flow plug was left on as no general heating of the bulb would have taken place.
 

1924 The WM type light weight engines introduced in l cyl, 6hp, 2cyl 12 hp and 4 cyl 24 hp form at 900 rpm. The
        injection spray was connected to the governor, gearboxes were used and starting was by salt peter touch
        paper.


1925 The BM type was introduced. This had all the NE advantages plus the cylinder heads did not enter the
        cylinders so far. i.e. the deep head, the NE sometimes being called the shallow head type. The result was
        better scavenging, increased compression pressure and thus additional power. Also the crankshaft,
        counterweights and clutch were larger whilst the connecting rod was lighter and the gudgeon pin hollow.
        Most of us have this type. E and M type engines could be converted to BM giving the following
        advantages:-

        1. Bhp up 10-20 % on lower fuel consumption.
        2. Oil saving, engine running indefinitely on light or no-load without aid of heating lamp (!)
        3. Increased life – no water drip.
        4. Greater flexibility due to degree of atomisation being variable between full and no-load by adjusting
        fuel injection spindle in its seat.
        Specific fuel consumption for 100 hp engine 0.55 lb/Bhp/hr so say 0.6 for our small units, but
        remember no gearbox losses.


1929 Lubrication box introduced with the NE improved. All pumps enclosed in the tank with a hinged cover.


1926 Quick start lamp introduced. Running on fuel oil start up was in 2 minutes.


1928 Gear boxes available for up to 120 hp.


1930 Cold start engine 400 hp at 275 rpm introduced.

 

The following table lists the revolutions of BM type engines with direct reversing at normal loads.

No of Cyl     Bhp     Rpm
     4             600      180
     4             400      275
     4             300      300
     4             240      375
     4             180      400
     4             120      475
     2             200      275
     2             150      300
     2             120      375
     2              90       400
     2              70       425
     2              60       475
     2              50       500
     2              40       550
     2              30       600
     2              24       650
     2              14       800
     1              75       300
     1              60       375
     1              45       400
     1              35       425
     1              30       475
     1              25       500
     1              20       550
     1              15       600
     1              12       650
     1               7        800

Remember that the 15 hp in canal boats are de rated 20’s and the 9’s de rated 12’s. Tug Worcester’s 30 the 20’s
with gearboxes and the Knawle double 25 are at the full rating.

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