• Cost effective solution for vibration reduction

  • Containment design provides fail-safe proven performance with more than 25 years in service

  • Lowest stiffness direct fixation fastener on the market

  • Available for special track work and guard rail application

  • HK Egg is available for up to 20-ton axle load


The ATP EGG Track Fastener reduces ground-borne vibration which ensures that buildings that adjoin transit tracks endure significantly less secondary noise. The ATP EGG is ideal for direct fixation environments, including slab, aerial structures  and tunnels. In service in the United States since 1983, the ATP EGG’s excellent acoustical performance, increased lateral stability and superior maintenance record is due to its unique design. Vertical forces are cushioned as rubber is placed in shear when ATP EGG deflects under load from passing trains.


The ATP EGG reduces ground-borne vibration and provides acoustical effectiveness achieved through its unique geometric design and high quality materials. With a top plate and frame constructed of corrosion resistant ductile iron its strength and endurance mean less maintenance and down time.  It has excellent electrical isolation with a natural rubber elastomer bond that allows the top plate to float.


The ATP EGG’s standard design includes two anchor bolt locations, one on each side of the rail and diagonally opposite. Locating anchor bolts at the perimeter of the fastener yields important advantages:


  • When properly torqued, no rail force can reach the anchor bolts

  • Under abnormal conditions any force that might reach the bolts would be buffered by the cushioning effect of the elastomer, isolating the top plate from the frame.




  • 17” Body length

  • 9” Body width Varies width across anchor bolt flanges (12"-15")

  • 2-3/4” Rail seat elevation (70 mm)

  • 5-1/2” Rail Base width (115# RE Rail)Weight




  • 50 lbs. Body

  • 0.5 lbs. Gage adjustment clip

  • 1.7 lbs. e-clip

  • Stiffness 55,000 lbs/per inch




  • Top plate, containment frame and gage adjustment clip are all ASTM 536, Grade 65-45-12 ductile iron casting




  • Natural rubber

  • Assembly Metal parts fully bonded together with elastomer

  • Anchor Bolts 7/8” diameter bolts or studs meeting or exceeding ASTM A-325.  Use lock washers in either case. If stud, nut should also meet or exceed A-325.




  • e-2055 clips



Note: Weights & dimensions are approximate, not exact.