Which Gauge Shut the Polyol Line?

On 23 October 2018 the Rhine gauge at Düsseldorf read 23 centimetres. Germany's waterways administration still publishes that number as the station's NNW, the lowest low water level in its record.

It stood for seven and a half years.

It went at a quarter past eight on the morning of Thursday 6 August, and on the desk's own pull of the WSV series the gauge has not been back above it since. That is 182 hours as of this evening's reading, which printed at 3 cm.

Covestro's letter went out the next day.

"Which gauge does the force majeure on your contract actually key off?"

The wires quote Kaub. Your polyol does not.

Every low-water headline this month has quoted Kaub. Kaub is the reference point for Rhine navigation, it sits at river kilometre 546, and it is roughly 198 kilometres upstream of Düsseldorf.

On 7 August, the day Covestro declared force majeure on polyether polyols from Dormagen, the Kaub gauge went up. Its daily mean rose 3.8 cm, from 20.3 to 24.2, and its daily minimum climbed from 18 cm to 23 cm.

Düsseldorf fell 6.1 cm on the mean that same day, from 21.0 to 14.9, with a daily minimum of 10 cm. Köln, the other gauge that brackets Dormagen, fell 4.2 cm.

The chart below runs both series on daily minima with each station's own record low drawn in.

So a buyer watching the number in the wire copy saw the river improve on the day their supplier stopped guaranteeing supply. Kaub did not go under its own 2018 record until just after midnight on 9 August, two days after the letter.

Chempark Dormagen sits between the Köln and Düsseldorf gauges. Nothing about Kaub governs what can tie up there.

Convert the gauges into water and the gap gets worse. WSV publishes, for each station, the fairway depth it maintains at the equivalent low water level, which gives you depth as TuGLW + gauge - GlW.

At Düsseldorf that is 250 + 3 - 91, or 1.62 metres of fairway tonight. On the worst day ever previously recorded there it was 1.82 metres.