During the height of the Cold War and postcolonial challenges to that new order, the Egyptian state built the Aswan High Dam (1960-1971) using a combination of U.S., European, Soviet, and Arab technology and engineering, a process that produced in a new cadre of experts who have been documented by scholars (Waterbury, Mitchell, Bishop, Shokr, Mosallam). Less examined are the various technologies employed in dam construction and the ways in which the dam as a massive technological artifact existed and changed over time as a collection of discrete but articulated technologies: from turbines to grout to the giant billboards that counted down the days remaining to milestones in construction. Scaling these different technologies for use by engineers, builders, and the public remained a central challenge of building such a massive structure throughout the 1960s. A key technology in this effort was a cross-sectional view of the dam that accompanied most reports of the progress of construction and that represented different levels of detail about the composition and structure of the High Dam in order to make engineering details legible to wider publics. This paper focuses on one core technology of the dam: a grout curtain developed to anchor the structure to the Nile riverbed, which contained unexpectedly deep layers of unstable material above the underlying bedrock—a design flaw in the original siting of the dam. Engineers across the cold-war political divide contested the specific structure of the grout curtain and its potential to safely stabilize the dam. Tracking changing representations of the grout curtain through the three prisms of the blueprint, the cross-section, and actual construction brings into view the politics of spectacle and oversight that were central to construction. Using state archives, construction plans and records, memoirs, newspaper coverage, filmic and literary sources, among other primary sources, this paper draws together a critical biography of the contested grout curtain to argue that debates over the safety of the dam structure were not hidden from public view, in contrast to popular conceptions of the lack of transparency of authoritarian states in sharing vital knowledge to its subjects. As such, this paper joins scholarly debates largely outside the Middle East about the role of technology in “scratching” rather than seaming together political communities (Mrazek; see also Abraham, Hecht), especially in the construction of hydraulic infrastructures (e.g., Teisch, Pritchard, Mukerji, Tischler, Miescher, Pietz, Carse).