Tag Archives: drop-lock

Effin stats

I wrote here about Maureen O’Sullivan’s questioning of ministers about Effin Bridge, the lifting railway bridge below Newcomen Bridge on the Royal Canal in Dublin. It seems that she would like a drop-lock to replace the bridge, thus enabling boats to pass under the railway at any time without interfering with the operation of the trains. Which would be very nice, but that it would cost over €5 million and cause significant disruption to the railway during construction.

I was distressed by Ms O’Sullivan’s failure to make any sort of economic case for the drop-lock or for any other measure that might allow for free movement of boats on that section of the Royal Canal. I said:

As the expenditure on reopening the Royal Canal is a sunk cost, I am all in favour of making its use easier — provided that it can be demonstrated that (a) there is a demand for increased use, (b) such increased use will have benefits that outweigh the costs of any improvements and (c) no alternative investment offers better returns. As far as I can see, Ms O’Sullivan has demonstrated none of the three: indeed I see no evidence that she has even considered them.

Ms O’Sullivan’s position might be described as favouring an increase in the supply of possible passages along that section of the canal, but I thought it might be interesting to know what the demand for such passages was, so I asked Waterways Ireland how many boats had passed under Effin Bridge in 2013.

I was wrong about the number of days on which the bridge was lifted: nine lifts were available altogether. Six were on Tuesdays, two on Saturdays and one on a Sunday (to facilitate the Dublin boat rally):

Tuesday 16 April 2013:           0 boats
Tuesday 30 April 2013:         10 boats
Sunday 5 May 2013:            24 boats
Tuesday 21 May 2013:           0 boats
Saturday 1 June 2013:           8 boats
Tuesday 18 June 2013:           2 boats
Saturday 20 July 2013:          3 boats
Tuesday 13 August 2013:       7 boats
Tuesday 17 September 2013:  4 boats

So that’s 58 boats in a year.

I asked what the cost was: I was told that Irish Rail charges €1200 per weekday lift and €2000 per weekend lift. I presume that Waterways Ireland itself incurs other costs, perhaps overtime at weekends, but I don’t know what they are. The cost per boat for each lift was:

Tuesday 16 April 2013:           0 boats: lift cancelled as no boats wanted it
Tuesday 30 April 2013:         10 boats: €120.00 per boat
Sunday 5 May 2013:            24 boats: €83.33 per boat
Tuesday 21 May 2013:           0 boats: lift cancelled as no boats wanted it
Saturday 1 June 2013:           8 boats: €250.00 per boat
Tuesday 18 June 2013:           2 boats: €600.00 per boat
Saturday 20 July 2013:          3 boats: €666.67 per boat
Tuesday 13 August 2013:       7 boats: €171.43 per boat
Tuesday 17 September 2013:  4 boats: €300.00 per boat

The total charged to Waterways Ireland (not to the boaters) by Irish Rail was €10800.00.

Suppose that a drop-lock had been built for €5000000. Would it be worth investing that amount to save an annual expenditure of €10800? I suspect not, although I am open to correction by anyone capable of calculating NPVs or other relevant measures.

It seems to me, though, that the case for any capital expenditure is weak while demand for passages is lower than supply. Perhaps Royal Canal enthusiasts might work on attracting more boats to the Dublin end, whether from the Shannon end or from the Grand and Liffey.