Which bearings are found in the B sump?

The bearings found in the B sump are indeed the 4R and 4B bearings. In gas turbine systems, the identification and placement of bearings are crucial in supporting and stabilizing the rotor assembly during operation. The B sump typically contains bearings that are essential for providing lubrication and support to specific components of the gas turbine.

The 4R bearing, for instance, is located in a position that allows for effective load distribution and helps in maintaining shaft alignment, thereby reducing wear and tear. The 4B bearing serves a similar purpose but might be positioned differently to facilitate the overall balance and functionality of the turbine's rotor.

Understanding the arrangement and function of these bearings aids in diagnosing issues related to turbine performance, vibration, and lubrication. Since the other options do not indicate the correct bearings associated with the B sump, they can lead to confusion or misdiagnosis in maintenance tasks. Recognizing the specific identification of bearings in particular sumps is critical for technicians working with gas turbine systems.