Gauging

[WJM]

OK - I have the basic principal, the more weight in the boat the lower it sat in the water, the less of the boat above the surface, measure the height above the surface, apply some maths and bingo, the weight of the cargo.

 

How exactly did the process work - what information was in the gauging table (four entries for measurement at the four corners?) and how did the maths work to produce the result?

 

 

Following on from that, were there any 'tricks' used to manipulate the results. At major canoe regattas we often have our boats weighed after a race. It is fairly routine for anyone whose boat is a borderline on weight to 'accidentally capsize' as they approach the weighing station to ensure the boat has a film of water all over the inside that the scrutineers cannot empty out. The commercial boatmen must have had their fair share of tricks either at the time of the original gauging or during operation.

[Liam]

I beleive that the boat's freeboard was measured when it was empty, and then measured again every time equal weights were added. Once they got to a certain point, whatever it was, for example 16 tonnes, they were able to guage how much the boat could take when it was sat "X" deep.

 

I'm guessing that a copy of these results were kept at guaging points over the system.

[WJM]

I kind of had that much already - I am trying to understand the actual calculations. If the boat is heavy at one end and light at the other (which it could well be) how was the maths done to arrive at the weight? What info was in the tables?

 

To throw another question into the mix - when did they stop gauging? - there were cargo boats still operating on the Southern GU in the 1980s. Were they still gauged then?

[magnetman]

I reckon take 4 measurements at each load weight then average the readings taken each side and end then use tables or a special slide rule to calculate a 'tons per inch immersion' equivalent for the particular boat. Narrow boats have a high 'block coefficient' so these calculations would be relatively straightforward.

[Hairy-Neil]

To throw another question into the mix - when did they stop gauging? - there were cargo boats still operating on the Southern GU in the 1980s. Were they still gauged then?

 

I believe annual licensing of commercial boats was introduced in the 1960s after lobying by the Willow Wren Co. that the tolls were uncompetitive and gave road transport an unfair advantage.

 

The Enviroment Agency still charge tolls for merchandise carried on the Thames and tug tolls for the passage of a lock by a registered tug (which could also have a cargo hold). Empty unpowered barges are toll free. The EA also act as an agent to collect a toll payment for the Port of London Authority on the semi tidal stretch of the river. However, I've never known them actually guage the boat, just taking your word for it on what you are carrying (or not). There is also an allowance for fuel for the boat's cabin stove, so you can carry, say 1 ton of coal that's not for sale and not have to pay a toll on it.

 

Its an unfair system in that it is more expensive to take an empty boat up the river paying tug tolls than a partially loaded one running on minimum merchandise toll. Working narrowboats that visit the Thames often carry a token load of coal to enable them to get the best rate.

[zenataomm]

Interestingly my post on this forum: -

Forum: History & Heritage · Post Preview: #161570 · Replies: 4 · Views: 210

 

And I'm still waiting to hear.

 

Yes they did measure the amount of dry at points along the side and took an average, and yes copies were kept at the various gauging points.

 

The sheets also listed the ropes, stove and dunnage that formed part of the boat's inventory.

[WJM]

Zen - any chance you could post the Gauging Table on the forum? Have you got it as a scan?

[zenataomm]

Zen - any chance you could post the Gauging Table on the forum? Have you got it as a scan?

They are large sheets, but I'll do me best!

[John Orentas]

Saw a clever contraption, I think in a museum somewhere, it had a stop that rested on the gunwale and a float at the bottom.. The gauged depth could be read off at eye level.

 

I remember too seeing a weighing machine installed above a dry dock, a much more accurate though expensive solution, I think it was designed for the initial gauging and documentation of new boats.

[Hairy-Neil]

The dry docks at both Braunston bottom and Marsworth top locks were originally built as guaging docks. Others likely survive elsewhere.

[carlt]

The dry docks at both Braunston bottom and Marsworth top locks were originally built as guaging docks. Others likely survive elsewhere.

Yes, which makes bending a plank into the bows, in Braunston Bottom lock, an interesting excercise.

[magpie patrick]

A few slight variations on this as I don't know much about gauging but...

 

I managed to cadge a ride on one of the Calder and Hebble coal boats in the 70's (well. Ok, Dad did and I went with him). Skipper was given a docket with how much he'd been loaded with.

 

I think there were three weighing machines: one in Cardiff on the Glamorgan Canal, one at Brimscombe Port and one on the Somerset Coal canal. the cardiff one is at Stoke Bruerne. The Cardiff and the SCC one were used to spot check accurately rather than just for unloaded boats. Does anyone know of any more machines or any more on how they were used?

[tony collins]

Yes, which makes bending a plank into the bows, in Braunston Bottom lock, an interesting excercise.

 

 

Thats if you can get over the cill to get in in the first place. I remember one day having the devil's own job of getting enough water over the cill to get "Panther" into the dock in the first place. Boaters coming down the flight were somewhat intrigued to be asked to keep one bottom paddle open on the second lock up whilst we tried to shift her off the cill of the dry dock!

 

BTW Nobody seems to have mentioned the "Weighing machine" at Stoke Bruene.

 

Tony

 

Edit: Whoops! Just noticed the post above.- sorry.

Edited December 14, 2007 by tony collins

[Hobbler]

There was a Gauging Dock above Factory Locks at Tipton on the BCN .

 

When a boat was first gauged set weights were loaded into the empty hold and the freeboard measurement taken as each weight was added . Mind you they did not always get it right and there are several photographs of boats actually sunk in the dock when too much weight was added.

 

There were various tricks that could be employed to "Increase" the load . Two I witnessed in the 50's was to hose down a dry load just before reaching a gauging stop and another was while the load was actually being gauged to distract the gauging clerk while he was taking the load measurement and try to get your mate or anyone else to stand on the gunnel on the same side as the measurement was being taken. Obviously most clerks were wise to this one but it was sometimes possible to get away with it.

[zenataomm]

Zen - any chance you could post the Gauging Table on the forum? Have you got it as a scan?

 

Scanned them, they've come out better than I thought, just come to post them on the thread and realised I don't have an eight year old to show me how.

I'll go back through the forum I'm sure there must be a how to do it somewhere, before I hit the bottle and give up on boats and canals for ever.

zenataomm

[zenataomm]

Good old SuperMalc, I might have guessed he'd be our saviour, does every forum have a SuperMalc?

So having followed his guide for dummies ........... here follows two scans of the guaging sheets ................

[Hobbler]

Of the items listed as on board I presume tarpaulins and side cloths are we now call top cloths and side cloths but what are deck and cabin cloths . Are deck cloths the same as tippetts or something different ? and are cabin cloths what was used to protect the expensive signwriting on the cabin sides ?

[Keeping Up]

Pretty close to the rule-of-thumb estimate of 1" per ton

[David Schweizer]

The Dry dock at Bradford on Avon on the K&A is still there, complete with the crane and original stone gauging weights. Some years ago a swinging gate was added to the canal end to replace the original stop planks, but apart from that it is prety well the same as it when it was built.

[carlt]

Of the items listed as on board I presume tarpaulins and side cloths are we now call top cloths and side cloths but what are deck and cabin cloths . Are deck cloths the same as tippetts or something different ? and are cabin cloths what was used to protect the expensive signwriting on the cabin sides ?

Photo of Lucy with, what I understand to be cabin cloths:

 

Rose usually had the cloths pulled all the way down, though.

 

The tarp over the back deck may be the deck cloth?

 

(Thanks, Alan, for sharing those wonderful two photos, btw)

Edited December 15, 2007 by carlt

[Hyperion 53]

A deck cloth is the cloth that fits over the deck board forming part of the cratch.

 

In the picture below you can see the deck cloth over the deck board on Badsey at Dadsford shed whilst President was being relaunched. In most cases you fit the deck cloth first, then pull the side cloths up and lay the top cloth over followed by the tippet on top. There aren't many boats running around these days with such cloths fitted.

 

[carlt]

Excellent! Thank you!

 

Was I right about cabin cloths? It's what Laura Carter called them when I was chatting to her some years ago.

Edited December 15, 2007 by carlt

[Hairy-Neil]

 

 

By dunnage do they mean:-

 

1. Loose packing material used to protect a ship's cargo from damage during transport.

2. Personal effects, baggage.

 

Or perhaps

 

3. Both of the above

Edited December 15, 2007 by Hairy-Neil

[carlt]

I understood "dunnage" to mean packing material.

[John Orentas]

I understood "dunnage" to mean packing material.

 

 

Collins new English;

 

"Loose wood of any kind laid on the bottom of a ship, to keep the cargo steady or prevent injury from bilge water".. "Etymology unknown".

Edited December 15, 2007 by John Orentas