Tuesday, 11 July 2017

Main North Line [3]: Clarence

I'm going to go a bit out of sequence here and put Clarence into the mix while also talking about some other things. I had to reinstall the computer that I do the maps on (it was updated to Xubuntu 17.10 which is actually a beta version), this let me update Qgis 2.99 to the latest master so it is all looking pretty good all round except for new bugs that seem to creep in but I do still have 2.14.10 running on Windows. No VMs seem to be able to network to the new installation and I can't be bothered trying to fix the issue as Windows 10 is OK with networking to this computer. Considering the short life of the entire project it is not worth the hassle. For the same sort of reason I had a look at the Nelson-Marlborough project section of NZ Rail Maps and instead of doing a whole lot of work to update that project to the current standard, I have just rolled the data into a bigger CanterburyWestland section that is now CanterburyWestlandNelsonMarlborough. So there are two sections for the whole South Island and three for the North Island instead of three each. The NM section was pretty small anyway as it only had about 100 km of the MNL and the Nelson line in it. So that just makes it real easy dealing with the MNL with the aerial photographs from the earthquake. At the moment I am just transferring data into the new CWNM section so it is all integrated properly. 

The issue in a Xubuntu component that caused long decimal values with a lot of extra zeroes in them to be displayed for distances of stations and milepegs is gone so that's great as well. But the digitising is worse in this new version and for me so tricky compared to 313ec55 that I am installing that version onto the mediapc so I can keep using it to finish the digitising without mucking around as I just don't have the time to muck around with everything needing to be finished by the end of the year. 

Another thing that has happened is that National Archives replied to my query about aerial photos of Alexandra and I have placed the order with them to have these scanned for my use so hopefully I should get these in a couple of weeks. This will probably not hold up the work still going on to finish revising the first part of the article which I have to make a priority to finish this week so I will have to drop the MNL work for a bit until I get the Otago Central stuff pushed along some more. So these aerials of Alexandra will probably not turn up in time to be useful for the OC part 1 but will inform the online maps which is a separate stage.

A construction photo of the Clarence River railway bridge c.1940. Although some sources claim Clarence used a combined bridge before this period, this was actually the first time the railway crossed the Clarence River. The old highway bridge was a kilometre upstream of where the railway bridge was built and there would have been some sharp curves to get the railway to it as well as running alongside a cliff face on the south side and adding several km in length to the railway route must have all been factors in deciding to locate the bridge where it is today.

What's really worth posting about is this is the first train to cross the Clarence River in eight months. This means trains can now go from Picton almost all the way to Kaikoura. Maybe they can actually go all the way to Kaikoura. You can see scaffolding around most of the piers; this suggests the repair work was concerned with the attachment of the bridge trusses to the piers. What we can also see is the bridge pier that has been underpinned on the right; this more or less means the extent of flood induced scouring in the riverbed has been so much that several piers have had new bases put around them to secure them.

 The whole bridge.

The south end and you can see quite a few underpinned piers here in this river channel which must be the main river channel of the Clarence River at this bridge with four piers underpinned in the water and a few more up out of the water by the looks of it.