{"id":44484,"date":"2026-06-18T06:07:00","date_gmt":"2026-06-18T10:07:00","guid":{"rendered":"https:\/\/briansolomon.com\/trackingthelight\/?p=44484"},"modified":"2026-06-16T19:03:35","modified_gmt":"2026-06-16T23:03:35","slug":"quadruple-fours-in-the-lead","status":"publish","type":"post","link":"http:\/\/briansolomon.com\/trackingthelight\/quadruple-fours-in-the-lead\/","title":{"rendered":"Quadruple Fours in the Lead."},"content":{"rendered":"\n

It is only a number, but I think catching Norfolk Southern 4444 leading a westward manifest freight on the Pittsburgh Line made for more interesting photographs than if a similar locomotive had carried a more common road number. This unusual type of numeral is known as a repdigit<\/em>.<\/p>\n\n\n\n

The freight consisted of more than 180 cars. In addition to 4444, a mid-train DPU provided extra power. This separation of locomotives is now common on many modern road freights. Among the advantages of DPU operation is a reduction in drawbar stress on the trailing coupler of the lead locomotive. This helps railroads operate and better control very long trains.<\/p>\n\n\n\n

The technique behind the photographs also merits examination. Among the benefits of modern digital processing is the ability to control and adjust color contrast to best suit the scene. These images would not have made especially compelling photographs on Kodachrome. However, by exposing digitally to maximize data capture and then processing the files to carefully place highlights and shadows while controlling contrast, it is possible to produce pleasing images in difficult lighting conditions.<\/p>\n\n\n\n

I like blending four concepts into a single essay. Each of these four paragraphs discusses a different topic relating to the photographs. A novice might ask what a repdigit has to do with DPU operations and photographic contrast control. The answer is simple: \u201cthese photographs.\u201d I don’t know that it needs to be any more complicated than that.<\/p>\n\n\n\n

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Tracking the Light Examines Railroad Photography!<\/em><\/p>\n","protected":false},"excerpt":{"rendered":"

This unusual type of numeral is known as a \u2018repdigit.\u2019<\/p>\n","protected":false},"author":1,"featured_media":44486,"comment_status":"closed","ping_status":"","sticky":false,"template":"","format":"standard","meta":{"_s2mail":"yes","jetpack_post_was_ever_published":false,"_jetpack_newsletter_access":"","_jetpack_dont_email_post_to_subs":false,"_jetpack_newsletter_tier_id":0,"_jetpack_memberships_contains_paywalled_content":false,"footnotes":"","_jetpack_memberships_contains_paid_content":false,"jetpack_publicize_message":"","jetpack_publicize_feature_enabled":true,"jetpack_social_post_already_shared":true,"jetpack_social_options":{"image_generator_settings":{"template":"highway","enabled":false}}},"categories":[6060,10,6108,48],"tags":[4527,5383,5131,8676],"jetpack_publicize_connections":[],"jetpack_featured_media_url":"https:\/\/i0.wp.com\/briansolomon.com\/trackingthelight\/wp-content\/uploads\/2026\/06\/NS_4444_Pittsburgh_Line_Linton_Hill_Road_Duncannon_PA_\u00a9BrianSolomon_DSC_6333.jpg?fit=2048%2C1252","jetpack_shortlink":"https:\/\/wp.me\/p2BVuC-bzu","jetpack_sharing_enabled":true,"jetpack_likes_enabled":true,"jetpack-related-posts":[],"_links":{"self":[{"href":"http:\/\/briansolomon.com\/trackingthelight\/wp-json\/wp\/v2\/posts\/44484"}],"collection":[{"href":"http:\/\/briansolomon.com\/trackingthelight\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"http:\/\/briansolomon.com\/trackingthelight\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"http:\/\/briansolomon.com\/trackingthelight\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"http:\/\/briansolomon.com\/trackingthelight\/wp-json\/wp\/v2\/comments?post=44484"}],"version-history":[{"count":1,"href":"http:\/\/briansolomon.com\/trackingthelight\/wp-json\/wp\/v2\/posts\/44484\/revisions"}],"predecessor-version":[{"id":44490,"href":"http:\/\/briansolomon.com\/trackingthelight\/wp-json\/wp\/v2\/posts\/44484\/revisions\/44490"}],"wp:featuredmedia":[{"embeddable":true,"href":"http:\/\/briansolomon.com\/trackingthelight\/wp-json\/wp\/v2\/media\/44486"}],"wp:attachment":[{"href":"http:\/\/briansolomon.com\/trackingthelight\/wp-json\/wp\/v2\/media?parent=44484"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"http:\/\/briansolomon.com\/trackingthelight\/wp-json\/wp\/v2\/categories?post=44484"},{"taxonomy":"post_tag","embeddable":true,"href":"http:\/\/briansolomon.com\/trackingthelight\/wp-json\/wp\/v2\/tags?post=44484"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}