Navigation, steam, Haarlem

Sunday 25^th June – to Haarlem – 11.6nm

We're following what is known as the Staande Mastroute, or mast-up route, north through the Netherlands. To guide us we have an excellent publication from the ANWB, unfortunately in a now rather out-of-date edition. The charts are usable although some new bridges have been built since our 2009 edition was published. Goudaaksebrug just south of Gouda wasn't in our book and nor was the Amaliabrug just to the north. Some bridges have new names just to confuse us (such as the Kaagbrug where we spent last night, which used to be called the Sassenheim) and the timetables for the bridge openings are often out of date too. It's been updated once in pencil (when we used it in 2014) and now we're using it in conjunction with a pdf file of up-to-date bridge timetables on Howard's mobile phone. Laborious but it seems to be working.

The mast-up route(s) across the Netherlands.
We didn't do pages 4 or 5 but came in to Dordrecht from the west at the very top of page5.
 Pages 6 and 7 got us to Gouda, on page 9 we forked left at Alphen then turned left to go to Haarlem via pages 18 and 19.
The route via pages 10 and 11 involves a night convoy through the middle of Amsterdam which we have always avoided.

Here's page 19

The blue boxes show yacht harbours and clubs suitable for stopovers and the red boxes are bridge timetables. Beware the asterisks! One year here we fell foul of well hidden messages such as “unless the river is NAP + 2m” or “but only on the hour for leisure craft” or, very sneaky, “for commercial traffic only but if opened leisure craft may also pass”. We have learnt to persevere with Google Translate on the small print – although Google struggles with NAP too. We knew the A was for Amsterdam and that it's about water levels but for the purposes of educating ourselves (and now you) we have found out from Wikipedia that it stands for Normaal Amsterdams Peil. This converts to English as Amsterdam Ordnance Datum, though I'd translate it as Normal Amsterdam Level. It's not just sea levels they have to worry about here, it's all the fresh water coming down the Rhine as well but they do seem to have that under control so far on this trip.

In the approach to Haarlem there is a museum on the theme of the constant battle the Dutch have with water. On previous trips we have hurried past on our way to the bright lights. Today we stopped to see what we'd been missing.

Cruquius Museum, very gothic in style, is a Victorian pumping station which, together with 3 others like it, pumped dry an enormous lake to reclaim the land. The figures on volumes and time frames are impressive. The building houses the world's largest steam engine - the main cylinder measures 3.66m across. The boilers are long gone now but we saw a demonstration of it in action powered by modern hydraulics

The pump was steam-driven and had six enormous boilers like this - all were scrapped when the pumping station was decommissioned in the 1930s - this is just the front end of one similar which was found in a scrap yard

That cylinder is 3.66m wide - cast in Cornwall

Up go the tops of the 8 arms lowering huge buckets outside which will lift the water 9m to the level of the river where it will run off

View upwards

Each of the 8 huge arms has a bucket which lifted 8 tons of water, five times a minute, from the level of the lake 9m below to here where it will flow off into the river Spaarn.  All 8 buckets came up at once so the engine was lifting 64 tons each time. That makes 320 tons of water per minute. Behind you can just see Bonify's mast where she's tied up in the river.

Steel flaps form the bottom of the bucket: they "feather" as the cylinder is lowered through the water, then the force of the water in the cylinder closes them across at the bottom to from the base of the bucket as it is lifted.  Technically Howard  says you'd describe this as a non-return valve. Hope you are keeping up!

As you might expect there are steam engines for sale here - several different models. Howard was pleased to find one very similar to the one he used to have (sadly lost in our workshop fire in 2009)