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David Caldwell Profile
David Caldwell

@roodave

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Engineer. Urban & rail transportation - cities - applied arts & sciences - major projects - regulation - competition Tweets represent personal views only

Sydney
Joined March 2010
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@roodave
David Caldwell
5 years
Road transport electrification presents a once in a century opportunity to address the user-pays element (currently petrol/ diesel tax) that contributes about half of the direct costs of road spending (including maintenance, administration, expansion, enforcement)
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@roodave
David Caldwell
2 days
Coincidental given today’s Austwitter culture war: walking past an Australian built 1970s recreational utility vehicle (Moke) parked behind a modern imported Sports Utility Vehicle/ pickup (Dodge Ram)
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@roodave
David Caldwell
2 days
Fascinating photo of a trolley bus in Hà Nội, Vietnam in 1989, and a damning caption in the Feb 1995 “Trolleybus Magazine” vol 32
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@taipan168
taipan168
2 days
It is well past time that the luxury car tax and a significant weight-based registration charge be applied to these monster American pickup trucks. https://t.co/x1qQ5ynFCj
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@roodave
David Caldwell
2 days
The saddest thing about the 40year precipitous rise of Sydney harbour-front property prices is that most of “hands on” blue collar people, who knew how to make use of it with slipways, fishing and work boats etc have been priced out, leaving mainly people who can only look at it
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@roodave
David Caldwell
2 days
Just learned an old acquaintance's former house in Sydney's Watsons Bay sold for almost $35.5m (probably a knock down/ land value) more that 6x what it sold for in 2010, about 12.5% YoY for 15 years. Safe-haven $s from China seem to be continuing undeterred
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@FilArons
Fil Aronshtein
3 days
Lately I've been seeing a very interesting major shift. Large, man-made things that used to be designed and build-planned like they’re architecture are being moved to be designed and built like manufactured products: Ships and data centers. Historically, these systems were
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@roodave
David Caldwell
3 days
The King's 2025 Christmas speech (which I missed because we don't have a TV, and I guess was otherwise under embargo until UK time). Strong messages of unity, shared values, hope, pilgrimage https://t.co/0yuRr4ztT7
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@MmarianneJoseph
Margaret Joseph
3 days
US President Roosevelt's 1940 speech on Fifth Columnists (those who befuddle, undercut and divide from within) remains as sharp and timely for the West as it ever did! A foreign "poison" of hate and betrayal.
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@johnrich
John Rich🇺🇸
6 days
Show this video to your kids…Wow😳
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@roodave
David Caldwell
6 days
instead, that economic achievement, good-will and support has been squandered on WSA metro (which isn't even technologically compatible with the Tullawong metro), and largely duplicating the capacity of the existing 4/6 track western rail corridor with Parramatta metro
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@roodave
David Caldwell
6 days
while everyone was high on the momentum and political support from the first (excellent) Tullawong - Sydenham metro, it could have beed directed to better connect the ~12km coastal radius of Sydney, e,g, Balgowlah, Seaforth, Brookvale, Dee Why, Maroubra, La Perouse
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@roodave
David Caldwell
6 days
Despite the "why not both?" apologism of advocates, politicised vanity projects like Western Sydney Airport Metro mean that building the most important metros, in the areas where people want to live most, with the most economic value, just don't happen https://t.co/rQGuy39hgG
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@ivanhzhao
Ivan Zhao
7 days
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@roodave
David Caldwell
7 days
A new electric tilt train on narrow gauge (3'6" 1067mm) and 1500V DC. Apparently JR Central have been experimenting with top speeds. I wonder if the got anywhere near Queensland Rails' Australian rail speed record achieved by narrow gauge tilt: 210km/h (in 1999)
@JPNStation
Japan Station
7 days
JR Central is developing new Series 385 to replace the Series 383 on the Limited Express Shinano. This service connects Nagoya and Nagano with 13 round trips per day. The new model features next-generation tilting control. Instead of relying on wheel rotation, the system uses
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@roodave
David Caldwell
7 days
this is Australia’s version of getting Al Capone on income tax fraud
@dannolan
dan nolan
7 days
Local councils having more power than asio is Australian excellence
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@paulg
Paul Graham
8 days
This graph from @pablogguz_ of Spanish fiscal contributions by age demonstrates an important fact. The 40 and 50 year olds are carrying both their kids and their parents. And not just economically. This is why it's hard to be middle-aged.
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@roodave
David Caldwell
8 days
I’m no longer passive. A response is required to introduce cultural and ideological restrictions to immigration, and intervene in and break the cycle of hatred and indoctrination which is already in Australia https://t.co/sJColKZLTy
@FranMooMoo
Francynancy
9 days
This is the next generation of Australians. Is it already too late?
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@roodave
David Caldwell
8 days
Is absent from the other side of the argument, where people like Bob Carr, former premier of NSW, and Clover Moore, Lord Mayor of Sydney, happily March with a subset of Islamic extremists on Sydney Harbour Bridge
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@roodave
David Caldwell
8 days
In past I have recognised this problem, but been quite passive about it, because i recognise that immigration restriction movement has a large overlap with right wing extremism and nazis (eg below) https://t.co/L2yOEDwJD9 but this level of restraint
@roodave
David Caldwell
11 months
@taipan168 I’m not braying or advocating for it, but I understand why others do. A material difference between our own home grown mental illnesses, a statistical certainty, and importing religious and ideological hatred of other nations
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