Questions tagged [transportation]

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Do high speed trains use ventilation and filtration systems similar to aircraft?

This article discusses the ventilation and filtration in aircraft: Ventilation rates provide a total change of air 20 to 30 times per hour. Most modern aircraft have recirculation systems, which ...
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Why are trams always electrified with DC, while trains can be electrified either with AC or DC?

Trains can be electrified either with DC voltage or with AC voltage. Various networks across various countries uses various standards. My question is however for trams, which are basically a lighter ...
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How do you calculate the chain tension required when compressing bulk material over a conveyor?

Bulk material is conveyed over a slat conveyor, and the material is leveled with overhead rollers while being transported in the conveyor to maintain an even material height. Most of these "levelers" ...
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Is there a particular reason the Moléson funicular is built as a giant bridge?

So I live in Switzerland and there is lots of funiculars in my country. Most of those were built between 1890 and 1930, and for most of those the line is on the ground most of the time, there is ...
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Why are different tractor trailer hitch configurations used in different regions of the US?

This may not be the best SE site for this question but I figured there had to be some engineering insight behind it- I've noticed in the western US tractor trailers have much longer hitches, like ...
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Does the Hyperloop One suspension require constant current through copper windings?

As a follow-up to How does the pressurized suspension of the Hyperloop not affect the tube pressure?, I believe (though I can't find where I read it now) that the Virgin Hyperloop One implementation ...
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speed-density relationship transportation question

I have the following questions: Would the capacity be the area under the curve? Or can I use this formula: $q_c = \frac{k_j \times v_f}{4}$ from the greenshields model, where the capacity flow is ...
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Why can't the 'special values' in the transportation fundamental diagrams always be determined?

Why can't the 'special values' in the transportation fundamental diagrams always be determined? For example: Why can't I always determine the Free-flow speed (𝑣A), Capacity (𝑞B), Critical density (�...
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