While the world was celebrating the holiday season, engineering history was being written deep beneath the ocean floor. A massive breakthrough was achieved at the Hainan Wanning 1,250-meter ultra-long subsea pipe jacking project. Operating in highly unstable, saturated sand layers prone to immediate collapse, the massive Tunnel Boring Machine (TBM) hit its designated target coordinates with pinpoint precision, marking a flawless full line breakthrough.
At the heart of this record-breaking offshore utility project was a critical piece of high-precision guidance hardware: the proprietary 1.5km Ultra-Long Range Green Laser Electronic Theodolite, developed and manufactured entirely by Changzhou DADI. Serving as the primary guidance backbone, this heavy-duty hardware provided an unyielding optical baseline through 1.25 kilometers of subsea darkness.

Spanning 1,250 meters under the open ocean, this intake pipeline project stands as one of the longest subsea micro-tunneling operations of its kind. The true engineering nightmare lay in the geology: a shifting, pure sand stratum heavily saturated by seawater.
"Advancing a massive shield machine through this stratum is like trying to drill a clean hole through a mountain of loose flour," noted the onsite technical supervisor. "The pressure is immense. If the guidance system drifts by even a few arc-seconds over this distance, the pipe jacking string will buckle or stall under the shifting seabed, leading to catastrophic structural failure."
Inside an unlined, dark pipeline stretching over a kilometer beneath the ocean, conventional red laser guidance systems fail completely. High air humidity, water vapor, and dust cause severe beam divergence and light attenuation, scattering ordinary lasers into useless, blurry halos long before they reach the target.
To conquer this extreme environment, Changzhou DADI deployed its specialized long-range green laser system. As captured in the project site footage, a hyper-focused, incredibly bright green laser beam pierces cleanly through the deep, misty void of the tunneling pipeline.
Leveraging DADI’s proprietary optical lens architecture, the green laser wavelength offers superior human eye visibility and advanced atmospheric penetration. Even at a distance of 1.25 kilometers without intermediate relays, the beam maintains high collimation and holds a tightly focused, crisp light spot on the receiving target of the heavy shield excavator.
The automated shield control system continuously tracks DADI's green laser spot through a digital crosshair matrix. No matter how violently the subsea ground shifted or how muddy the tunnel air became, the boring machine followed this locked "green lifeline" straight to its target, achieving a historical breakthrough with negligible deviation.
What does this real-world success story prove to B2B procurement officers?
It proves that DADI hardware is field-tested under extreme conditions. When you source our Theodolite systems or high-precision total stations, you are investing in field-proven technology. We don't just test our optics in pristine labs; we prove their reliability under millions of tons of ocean pressure.
The successful breakthrough of the Hainan subsea project serves as a practical, national-level validation of Changzhou DADI's industrial design and optical consistency. We provide robust manufacturing backing, direct factory engineering consultation, and reliable hardware tracking for distributors handling premium surveying equipment globally.




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