User:Reboelje/sandbox

=Opduwer= An opduwer or opdrukker is a small towboat that was used in the Low Countries in the first half of the twentieth century to propel inland sailing barges and other unpowered watercrafts. As such they replaced the man or horse that towed the ship from shore at times when sailing was impossible from lack of wind or maneuvering room in tight canals.

=History= Transport by water was until far into the 20th century the only practical way of moving bulk cargo in the low lying regions of the Netherlands. Sailing was the preferred method of propulsion but lack of wind or maneuvering room in canals meant that towing by horse or by the skipper and his family was also a common occurrence. This was hard labour and the going was slow. The opduwer was invented around 1910 when the internal combustion engine started to get adapted to marine applications. However fitting an engine and propeller to the existing sailing barges was found impractical because of the hull shape and construction while the engine room took up valuable cargo space. Also some local governments taxed motor-powered barges higher than sailing barges as the former were thought to damage the canal shores. In stead the engine was built into a rowing boat or a purpose built boat that was lashed to the stern of the barge. Opduwer liturally means pusher. The small towboat was owned by the barge skipper and therefore towboat and barge commonly stayed together. The combination was often steered from the barge by the barges rudder, while throttle and reversing gear were operated by strings or a boat hook. The design of the opduwer evolved to a kind of miniature tugboat and was built by shipyards, often from leftovers from the construction of larger ships. Opduwer usage declined by the 1940's as engines were fitted into the barges and the relatively small barges themselves became commercially inviable as more cargo was transported over land. A large number currently survive as pleasure craft.

=Design= Opduwer sizes range from about 4 to over 6 meters, larger examples are commonly categorized as tugboats. The type of engine was diverse. In the early years a recycled car engine was popular, for example from a T-ford. There was even a conversion kit available to let the T-ford engine run on the cheaper kerosene. Later stationary engines from Lister and Deutz, fitted with reversing gears, became common as well as proper small marine engines from for example Brons, Kromhout and Samofa. The amount of horsepower of these engines may have been relatively small by todays standards but the weight of the early engines was significant making the opduwer sit low in the water and leaving only a modest freeboard. Some opduwers are completely open while others have an engine room to protect the engine from the weather.

History
De Olifant was originally built at Oostwold, Groningen in 1856 where it drained the Oosterwolderpolder. It was made superfluous when a new canal to sea was dug to drain water from the polder. In 1867 it was moved to Burdaard to drain polder De Olifant. The cost of purchase and re-erection was ƒ2,000. After a summer drought it was decided to add the function to pump water into the polder from the outside system of canals by adding an extra Archimedes' screw in 1914. This functioned until 1945. By then water in the IJsselmeer had desalinated enough to be let into the province and the water level in the canals during dry summers didn't drop as much. The mill kept its drainage function until 1970, though by then a diesel engine had been added to power the larger screw during periods with little wind. Waterboard De Olifant is merged with others to a much larger waterboard in 1968 and two years later a large scale land redistribution project means the end of the working life for De Olifant and three other drainage windmills, their function being taken over by a pumping station. The mill is now no longer connected to water outside the polder. The project also includes the construction of a road through the polder releasing the mill from its isolated location and funds are allocated to the restoration of the mill. After the restoration the Olifant is sold to windmill foundation De Fryske Mole in 1976. Over the years several repairs and restorations are done and by 1992 all three screws are usable again. De Olifant is in 2006 the first to be fitted with a new type of stocks that can be split in two so they can be hot-dip galvanised which is expected to double the lifespan.

The mill was sold to Stichting De Fryske Mole on 20 June 1977. Restoration was carried out in 1978-79 and again in 1991.

Millers
Bachelor Van der Leest operates the mill for half a century De Vries is only 19 years old in 1964 but his father was also miller. He moves to Oudkerk and is currently (volunteer) miller on the Oudkerker molen. Volunteer miller operating the windmill for 25 years.
 * 1879 - 1929 Siebe van der Leest
 * 1929 - 1964 Tjerk van der Meulen
 * 1964 - 1968 Eeuwe de Vries
 * 1986 - 2011 Jaap Terpstra