Tag Archives: yarrow

Friday 13th – unlucky for us, and performance data

Lady Luck

Took Befur out for a tour of the lake yesterday, enjoying a day of early autumn sunshine. Conscious that it was a fated day, I was expecting some drama!

Lou managed to (very narrowly) avoid a dunking while we were boarding, so I thought we might of escaped. However, bad planning on my part resulted in us getting blown onto a jetty on the lake, which was (unbeknown to us) fitted with large bolt ends projecting out to catch people in exactly our predicament – so more filling, sanding and re-painting required over the winter to repair a pair of gouges in the hull – bugger!

Performance Testing

One of my objectives for the trip, was to collect some performance data, and the map below (click the link and it should open in google maps) shows the route and the waypoints with speed, direction etc. (clicking on these will give performance data for each bit of the trip).

https://www.google.com/maps/d/u/0/edit?hl=en&hl=en&mid=1qv-Q4JREXMB5lKKMXQmANtZhy-Hxu3DD&ll=54.607108645724125%2C-2.8355938095091915&z=16

The net of this experimentation produced data on two “stable modes” of operation.  All of this at a boiler pressure cycling between 185 psi and 225 psi.

For the record we are now operating with a gear-up ratio from engine to propeller of 1.45:1 and a 21″ x 19″, 3 bladed, left hand prop.

At “cruising speed”

At this speed we are operating with a HP pressure of 60-70 psi, and an LP pressure of around 16 psi and a vacuum of about 10-inches. The engine is turning at between 175 rpm and 125 rpm (when alternator is charging). The map tells us we are moving at about 3 mph (2.6 knts), it was running into fairly light winds, so this data seems realistic.

At “flank speed”

This is about as fast as I feel happy running the plant, and is resulting in the engine slightly outrunning the boiler with a sustained boiler pressure of about 170 psi.. HP pressure is 135 psi, LP pressure 28 psi, vacuum of 14-inches. The engine is turning at 300 rpm and the log tells us she is making between 6.5 to 7.2 mph.

…so with a computed hull speed of just under 8 mph we still have a way to go on the performance stakes.

Those with better maths than I might be able to turn this into some meaningful performance data for the engine hull.

We also had the time to check the depth sounder and it certainly seems to work, with the audible alarm providing some confidence for the helms-person when we are running out of water!

…onwards, it will be “dragging out” time in the next few weeks, and then we can fix the outstanding mechanical issues, ifx the knocks and bangs, fit the mast and figure out how to stop the water getting into the cabin roof!

Burner Fixes

Just a quick note to record the changes we made to the burner, following the failures on Windermere and Ullswater.

The conclusion was that these failures were mostly heat related. But also we fitted three new control boxes to the burner before we found one that worked!!…

The solutions were:

  • Fit a heat absorbing blanket to the outside of the boiler casing to reduce the radiated heat impacting the burner.
  • Fit an external duct to cause the intake air to be drawn via the control-box and ignition transformer assemblies (to help cool them)
  • Strip and rebuild the burner, fitting new magic eye, solenoid, control box, ignition transformer, motor capacitor and a somewhat worn pump drive coupling.

As noted in an earlier post, this seems to have done the job, so here are some pictures:

A Goal Achieved!

Well that worked!

It would appear that the work on the burner paid off. Yesterday we had a fine day’s trip on Ullswater, from the marina at Watermillock, all the way to Glenridding without a single problem – virtually the full length of Ullswater. (About 3½ hours steaming). The first time we have managed the full length of the lake!

We took most of it at a leisurely pace, with a couple of bursts of speed to avoid yachts out racing…. Continue reading

A final video: Everything running on the bench

First Fix the Bugs!

Following on from the Boiler test, and a quick trial we identified just over 20 items that needed some attention. So a week later, with all these items fixed (from leaking valves to painting and plating valve gear components), we are ready to try again. Continue reading

A Boiler Full of Steam

Well the 10th November 2017 marks a major milestone – the boiler passed its initial inspection and steam test, and is now certified for use. (big smiles all round).

Picture of Engine, Boiler Etc. ready for test

Sadly, everything was too frenetic to take pictures during the steam test – but here it is just before we pressed go!

John, our inspector from SBAS Ltd (the SBA’s Boiler Inspecting Company) had been booked to arrive at 3:00pm – at 9:00am I set about final sealing of the try-cocks on the sight gauge – at 1:30pm I nearly called to cancel the appointment as no amount of fiddling and fitting would make them seal, with a constant drip from each of them at anything above 50psi 😦 Continue reading

All Pumped up!

Well a definite milestone was reached today; the boiler passed its official initial hydraulic test at 500psi conducted by our Boiler Inspector.

It will never need to be pressed that hard again, next we have a 375psi test with all the ancillaries fitted (gauges, valves, plumbing etc.) then we put some fire in its belly and prove that the safety valves will stop the pressure going more than 10% higher than its 250psi operating pressure – then we will be allowed to insure it and use it in anger!!!

This might seem like a bit of a palaver, but a boiler failure will typically kill everyone within many feet – so it pays to take care. Continue reading

Boiler Insulation and Funnel

Just a quick note on recent days’ work. We have been insulating the inner boiler casing and installing the funnel (at a jaunty angle)!

The boiler has two casings- one surrounding the burner, tubes etc. (the hot stuff) and an outer one of wood, with an air-gap in-between to keep passengers safe. This also includes a double skinned chimney (also to keep people safe – Lou has quite a scar from another steamboat where the funnel was not lagged or double skinned). Continue reading

Finishing the Superheaters & Boiler Casing

Work on the Boiler continues with the finishing and installing of the Economiser (pre-heats the incoming water to the boiler using waste heat from just before the flue) and the Superheater (adds energy to the steam on the way to the engine, again using waste heat from the flue gasses.

Milling and Drilling the Econo/Superheater Headers

As noted in the last post, I decided to mill the recesses in the two halves of the headers, as there is a lot of metal to shift, and with the “ripping” milling cutters this was by far quicker. (some pics)….

Milling Recesses in Headers

Milling Recesses

O-ring milling set up

O-ring milling set up

Some finished headers

Some finished headers

 

 

Continue reading