Updated 14 Jun 2014

River pipe with scale

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River pipe with scale.

HISTORY

of Bear Mead River scale

    In Aug 2003 it was decided to attempt to measure and record the height of the Dorset Stour daily at Bear Mead.
  • A place was chosen, accessible from the bank but deep enough to have river water in a severe drought, just downstream of a large goatwillow bush which should prevent clogging of the scale by floating vegetation [see 2701]. A 6-foot length of scaffolding was obtained and hammered deep into the gravel bed with a post-rammer, forming a strong anchor for the proposed round white plastic pipe with centimeter scale in acrylic paint. The scale could be read with fieldglasses from the bank. A level range of 3 meters was expected, and an arbitrary zero-point scale chosen from 100 cms to 400 cms [see 3133]. After many false starts, a pipe with ID of 51 mms (2 inches) was chosen which just fitted round the scaffolding. Occasional clearing of surrounding reeds was necessary; this could be done from the bank [see 3241]. Similar pipescales were placed in 5 other parts of Bear Mead.
  • This worked well for 9 years until a series of lengthy floods (reaching 390 cms in 2012) eventually snapped the pipe where it cleared the scaffolding [see 3361]. More internal strength was needed to reduce bending like 2.5 metre metal pipe.
  • A thicker form of pipe was located on Ebay (ID=51mm, OD=60mm) and bought. This was ordered in two lengths (90cms and 200 cms) to enable the author to erect the piping while standing knee-deep in mud that overlies the gravel on the river bed at this point. A scale was drawn that could be read even if the pipe rotated in strong river flow [see other styles]. An external post to prevent such rotation could not be used as vegetation collected around it, blocking a view of the scale [see 3429].
  • A redesign was made, incorporating the 2.5 metre metal pipe for strength, inside a 3 metre 40mm plastic pipe, inside the outer 2 inch plastic pipe. It is hoped this will be strong enough to resist breaking even in long floods [see 3430]. A 50mm short pipe kept the two 60mm sections co-axial.
  • To round off the new pipe-scale, a 6-inch spherical toilet float was painted with two faces, connected to 20cms of 43mm piping, and lowered into the top of the white pipe-scale from the bank with a 2 metre wooden rod and hook. Later, a 7-inch threaded rod served as ears to allow turning. See a sketch of the whole assembly in image [01].
  • Maintenance. The pipe needs to be removed, cleared of crud and repainted 4 times per year, say April, June, Aug and November, when the river height is less then about 160. A standby set of pipescales and head needs to be ready to replace the old. Reeds need to be occasionally cleared from round the pipe with deck shoes and garden shears. Damp crud removed with bucket, warm water, soft brush and washing-up liquid. Maintenance on 19apr2014, 13jun2014.
  • Strength. The new design of pipe-scale withstood 3 months of almost continuous flood, high and fast river during 15dec2013 - 06mar2014 with no apparent mechanical failure.
3449 27may2013

Old design

0265 31oct2007
0376 23nov2007
0515 13jan2008
2190 18jan2010
2701 31jan2011 Level=160
3133 01may2012 Level=376
3210 08jul2012
3218 08jul2012
3241 11jul2012
3288 13oct2012
3292 13oct2012

Problems

3305 02nov2012
3307 05nov2012
3361 29nov2012 Pipe snapped by long floods.
3429 10may2013
3403 24apr2013
3404 24apr2013
3431

New design

3428 10may2013 New pipescale design. Surrounding banks and river Stour.
3424 10may2013
3425 10may2013
3426 10may2013
01 27may2013 Sketch for a new design.

Needs
To remove lower pipe for cleaning in the summer, special equipment is needed
and the upper pipes need to be removed in a particular order. Maximum river
height for this operation is 164. The river bottom around the pipescale has
deep mud above solid gravel, special footwear is needed and feet need
thorough cleaning afterwards.
3430 10may2013 Piping used.

3432 Materials for painting scale

Other styles

of Gauge Board scale
G1
G2
G3
G4
G5
G6
G7

Compiled, formatted, hyperlinked, encoded, and copyright © 2013, John Palmer, All Rights Reserved.