Locale : North America (English)
Create document Page
Review document
Page Added

Exploring Grand Central's century-old steam system

Grand Central Terminal was designed and constructed between 1903 and 1912, when district heating and steam distribution was in full development in NY. An extensive network of steam tunnels is located beneath Grand Central.


Some parts of Grand Central's steam system have been in operation for over 90 years. Steam is provided by Con Edison and distributed to various internal and external clients in Midtown East.

Because of the age of the system, it has largely been undocumented. Metro North Railroad commissioned an assessment of the steam system in order to assess and identify all equipment and document equipment condition.


Mott MacDonald was retained to provide a comprehensive and detailed assessment of the existing steam system. This included site surveys to identify all equipment and a condition assessment of all live steam system pipework and elements (anchors, valves, etc).

No accurate as-built drawings existed and the team was also tasked with development of highly detailed 3D CAD models of the entire live steam distribution network below Grand Central. All steam system elements were incorporated into a single database, with linked photographs, new identification tagging and condition ratings. A 3D CAD model of the steam system was produced using advanced laser scanning techniques (accurate to 1/8 of an inch or 3.2 mm).

In order to assess the condition of the distribution network, we performed nondestructive testing using Computed Radiography at over 2,000 locations. This allowed pipe wall thickness to be determined without disturbing pipe insulation. Finite Element Analysis using computer modeling was also performed to determine areas where the steam pipes were being overstressed.


Based on our findings, short-term recommendations were made to address immediate system safety risks and code violations.

Long-term recommendations were made to optimize overall system operation by improving energy efficiency, improving maintenance access and introduce redundancy in the event of steam distribution failure.

Mott MacDonald's recommendations will help Metro North to develop a rehabilitation plan to ensure safe and efficient operation in the future.

icon-arrow-down-sml icon-arrow-left-lrg icon-arrow-left-sml icon-arrow-right-lrg icon-arrow-right-sml icon-arrow-up-sml icon-champions icon-close icon-download icon-education icon-email icon-grid-view icon-language icon-link-to icon-list-view icon-location icon-login-register icon-minus icon-more icon-phone icon-plus icon-recently-viewed icon-search icon hash key-facts-corner-sash quote-underline social-icon-facebook social-icon-googleplus social-icon-linkedin social-icon-twitter social-share-icon-facebook social-share-icon-facebook social-share-icon-googleplus social-share-icon-googleplus social-share-icon-instagram social-share-icon-instagram social-share-icon-linkedin social-share-icon-linkedin social-share-icon-twitter social-share-icon-twitter social-share-icon-youtube social-share-icon-youtube sina-weibo MM-Shape01-Quote-Views MM-Shape03-Quote-Locations MM-Shape05-Quote-Projects MM-Shape12-Quote-Sectors MM-Shape13-Quote-Expertise MM-Shape14-Quote-About-Us MM-Shape14-Quote-Careers checkmark icon-expand-view icon-apply-now menu sphere icon-cookies icon-legal icon-registered-companies target rotate-screen video-replay-flat video-replay audio-mute audio-play