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Eli

@eli-d.bsky.social
292 followers 613 following 31 posts

THWg

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Eli @eli-d.bsky.social · 04/10/2026
Yes it’s the same image, but you posted a picture of a screen displaying the image rather than the image itself. As an example, do you think this index card is actually slanted? Or does the position of my phone as I took this picture distort how the card looks?
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Eli @eli-d.bsky.social · 18/02/2026
are you sure about this math? I have Italy beating the US with a 29 cm LSD in their last match, as they have the best LSD in case of a tie in DSC. I could very well have made a typo entering the data though
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Eli @eli-d.bsky.social · 10/02/2026
TCRP 155 calls for 14’ when placing catenary poles between ballasted tracks, which the typical section is calling for
TCRP 155

2.3.3.3 Vehicle Clearance to Wayside Obstructions and Other Tracks

It is not unusual to have clearance restrictions on an LRT line that cannot be either simply or economically altered. In such cases, the track designer should coordinate with the vehicle and structural designers to ensure that the vehicle dynamic envelope considers these limitations so that adequate clearances result. Vehicle dynamics are governed by the car's suspension systems) and, therefore, indirectly by numerous factors of track and vehicle interaction. For multiple-track situations, multiple clearance envelopes must be considered. Overlapping of the vehicle dynamic envelopes from adjacent tracks obviously must be avoided. The resulting requirements will dictate minimum track centers and running clearances for tangent and curved track, including construction and maintenance tolerances as input to the track alignment calculations.

In general, the absolute minimum tangent track centers for vehicles of normal width (e.g., 2650 mm / 8.7 feet) for rigid trackforms (direct fixation or embedded) are 13 feet 6 inches [about 4.15
m] with a catenary pole between the tracks. If the poles are outboard of the tracks, 11 feet [about 3.35 m] is the typical minimum spacing. Tangent track center spacing for ballasted track is typically 6 inches [15 cm] greater than those for rigid trackform track due to greater allowances for construction tolerances and shifting of the tracks over time. Track curvature and superelevation increase these dimensions. These issues are discussed further in Chapter 3, Article 3.8.
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